Proofs - ProvenTrue

P
r
o
o
f
s
Given: TA ≊ TO;
PAD ≊
POD
Prove: PT is the ⊥ Bisector of
AO
Boat Shape Proof
[Boat Shape Prf]
Statement
Reason
1. TA ≊ TO
1. Given
2. TA = TO
2.
3. T is on the ⊥ Bisector of AO
3. PtsOn⊥Bis IFF Eqd
4.
4. Given
PAD ≊
POD
s ≊ IFF Meas =
5. PA ≊ PO
5. Isos△SidesIFF⊀s
6. PA = PO
6.
7. P is on the ⊥ Bisector of AO
7. PtsOn⊥Bis IFF Eqd
8. PT is the ⊥ Bisector of AO
8. 1LineThruPt ⊥
s ≊ IFF Meas =
Given: XZY ≊ XYZ; X is the
midpoint of VW; △XVZ and
△XWY are right △s
Prove: XVC ≊ XWY
Embedded Shape Proof
Statement
1.
XZY ≊
[Embedded Shape Prf]
Reason
XYZ
1. Given
2. XZ ≊ XY
2. Isos △SidesIFF s
3. X is the midpoint of VW
3. Given
4. VX ≊ WX
4. Segment Midpoint
5. △ XVZ and △XWY are right △s
6. △ XVZ ≊ △XWY
⁂
5. Given
6. HL Right △ ≊
Given: P is the circumcenter of
△XYZ
Prove: P is the same distance from
X, Y and Z
Circumcenter Theorem Proof
[CircumctrThm Prf]
Statement
1. P is the circumcenter of △XYZ
Reason
1. Given
2. P lies on the perpendicular bisectors of XY, YZ and XZ
2. △ Circumcenter
3. PX = PY
3. Pt On⊥BisIFFEqd
4. PY = PZ
4. Pt On⊥BisIFFEqd
5. PX = PY = PZ
5. Transitive Prop
6. P is the same distance from X, Y and Z
6. Dist PointTo Line
Given: m 2 = 90 °
Prove:
1 and
3 are
complementary
Acute
Statement
s RIght △ Proof
[Acute s RIght△ Prf]
Reason
1. m 2 = 90°
1. Given
2. m⊀1 + m 2 + m 3 = 180°
2. Sum Interior
3. m⊀1 + 90° + m 3 = 180°
3. Subst Prop
4. m⊀1 + 90° + m 3 - 90°= 180° - 90°
4. Subtr Prop
5. m 1 + m 3 = 90°
5. Combine Terms
6.
6. Complementary
1 and
3 are complementary
s△
s
Given: B is the midpoint of AE
and CD
Prove: △ABC ≊ △EBD
Common Midpoint Proof
[Common Midpt Prf]
Statement
Reason
1. B is the midpoint of AE
1. Given
2. B is the midpoint of CD
2. Given
3. AB ≊ EB
3. Seg Midpoint
4. CB ≊ DB
4. Seg Midpoint
5.
ABC ≊
EBD
5. Vert ical s ≊
6.
ABC ≊
EBD
6. SAS
≊
Given:
1 ≊
3;
A ≊
B; AF
≊ FB
Prove: △AFE ≊ △BFD
Half Star Proof [Half Star Prf]
Statement
Reason
1.
1 ≊
3
1. Given
2.
1=
3
2.
3.
2=
2
4.
1+
2=
5.
AFE =
1+
6.
BFD =
3+
7.
AFE =
BFD
7. Substitution Prop
8.
AFE ≊
BFD
8.
9.
A≊
3. Reflexive Prop
3+
2
2
B
10. AF ≊ FB
s ≊IFF=Measure
11. △AFE ≊ △BFD
2
4.
Addition
5.
Addition
6.
Addition
s ≊IFF=Measure
9. Given
10. Given
11. ASA △ ≊
Given: AG ≊ EG; GM is a
median of △AGE
Prove: △MAG ≊ △MEG
Statement
Median Proof
[Median Prf]
Reason
1. AG ≊ EG
1. Given
2. GM ≊ GM
2. Reflexive Prop ≊
3. GM is a median of △AGE
3. Given
4. M is the midpoint of AE
4. Def Median
5. AM ≊ EM
5. Def Midpoint
6. △MAG ≊ △MEG
6. SSS △ ≊
Given: Exterior
s
1 and
Prove:
Exterior Angle Theorem Proof
Statement
4; Interior
3
1+ 3=
4
[Exterior
Thm Prf]
Reason
1. Exterior
4
1. Given
2. Interior
1 and
3.
4 and
2 are a linear pair
3. Linear Pair
4.
4 and
2 are supplementary
4. Linear Pair Supp
5.
4 + 2 = 180°
5. Supplementary
6.
1+ 2+
3 = 180°
6. Sum
7.
1+ 2+
3=
4 + 2
7. Transitive Prop
8.
1+ 2+
3-
2=
8. Subtraction Prop
9.
1+ 3=
4
3
⁂
2. Given
4 + 2- 2
s△
9. Combine Terms
s
Given:
1 ≊ 2;
3 ≊ 4
Prove: △RAY ≊ △BAN
Semaphore Proof
[Semaphore Prf]
Statement
Reason
1.
1. Given
1≊
2
2. RA ≊ BA
2. Isos△ SidesIFF s
3.
3. Given
3≊
4
4. Isos△ SidesIFF s
4. YA ≊ NA
5.
RAY ≊
BAN
6. △RAY ≊ △BAN
5. Vertical
6. SAS △ ≊
s ≊
Given: △ABC is isosceles; DE ||
AB
Prove: △DEC is isosceles
Rock Climbing Proof
Statement
1. △ABC is isosceles
[RockClimbingPrf]
Reason
1. Given
2. AC ≊ BC
2. Isosceles △
3. m A = m B
3. Isos△ SidesIFF s
4. DE || AB
4. Given
5.
A ≊
1
5. Corresponding
s
6.
B≊
2
6. Corresponding
s
7.
1≊
2
8. DC ≊ EC
9. △DEC is isosceles
7. Transitive Prop ≊
8. Isos△ SidesIFF s
9. Isosceles △
Given: △TJC an isosceles △;
△TKC an isoceles △
Prove: △TAC is an isosceles △
Nested Triangles Proof [Nested △s Prf]
Statement
Reason
1. △TJC an isosceles △
1. Given
2. TJ ≊ CJ
2. Isosceles △
3. TJ = CJ
3. Segs ≊ IFF Lens=
4. J is the same distance from T and C
4. Distance
5. J is on the ⊥ bisector of TC
5. PtsEqdIFFOn⊥bis
6. △TKC an isosceles △
6. Given
7. TK ≊ CK
7. Segs ≊ IFF Lens=
8. TK = CK
8. Isosceles △
9. K is the same distance from T and C
9. Distance
10. K is on the ⊥ bisector of TC
10.PtsOn⊀ BisIFFEqd
11. Line segment AJKM is the ⊥ bisector of TC
11. 1LineThruPt⊥
12. TA = CA
12. PtsEqdIFFOn⊥bis
13. TA ≊ CA
13. Segs ≊ IFF Lens=
14. TAC is an isosceles △
14. Isosceles △
Given:
1≊
2;
G≊
P; GI ≊
PW
Prove: BG || PW
Horizon Proof
Statement
Reason
1.
1≊
2.
1 and
3 are a linear pair
2. Linear Pair
3.
1 and
3 are supplementary
3. Linear Pair Supp
4.
2 and
4 are a linear pair
4. Linear Pair
5.
2 and
4 are supplementary
5. Linear Pair Supp
6. ⊀3 ≊
7.
G≊
2
[Horizon Prf]
1. Given
4
6. SuppsTo ≊ s ≊
P
7. Given
8. GI ≊ PW
9. △BIG ≊ △WUP
10.
5≊
11. BG || PW
6
⁂
8. Given
9. ASA △ ≊
10. Corr Pts ≊ △ ≊
11. AIA ≊ Lines||
Given: △RST is equiangular
Prove: △RST is equilateral
Equiangular Equilateral Proof [Eq EqLat Prf]
Statement
Reason
1. △RST is equiangular
1. Given
2.
2. Equiangular
S≊
T
3. RS ≊ RT
3. Isos△SidesIFF s
4.
4. Equiangular
R≊
S
5. ST ≊ RT
5. Isos△SidesIFF s
6. ST ≊ RS ≊ RT
6. Transitive Prop≊
7. △RST is equilateral
⁂
7. Equilateral
Given: RS ≊ CS; ⊀ 2
⊀3
Prove: RY ≊ CY
Statement
Barred Door Proof [Barred Door Prf]
Reason
1. RS ≊ CS
1. Given
3.
3. Isos△ SidesIFF
2. △RSC is an isosceles △
1≊
4
2. Isosceles △
4. YS ≊ YS
4. Reflexive Prop ≊
5.
2≊
3
5. Given
6.
5≊
6
6. Third
7. △RYS ≊ △CYS
8. RY ≊ CY
Thm
7. ASA △ ≊
8. Corr Pts ≊△ ≊
Given: R is the incenter of
△JKL
Prove: R is the same distance
from the sides of △JKL
Incenter Theorem Proof
Statement
[Incenter Thm Prf]
Reason
1. Draw RX ⊥ JK
1. 1LineThruPt ⊥
2. RX is the distance between R and JK
2. Dist Pont To Line
3. Draw RY ⊥ JL
3. 1LineThruPt ⊥
4. RY is the distance between R and JL
4. Dist Pont To Line
5. Draw RZ ⊥ KL
5. 1LineThruPt ⊥
6. RZ is the distance between R and KL
6. Dist Point To Line
7. R is the incenter of △JKL
8. R lies on the
9. ⊀YLR
bisectors of
J, K and
7. △ Incenter
L
⊀ZLR
8. Dist Point To Line
9. ⊀ Bisector
10. LR
LR
10. Reflexive Prop
12. RY
RZ
12. CorrPts △
11. △YLR
△ZLR
13. ⊀XKR
⊀ZKR
14. RK
RK
16. RX
RZ
17. RX
RY
15. △XKR
△ZKR
11. HA Right △
13. ⊀ Bisector
14. Reflexive Prop
15. HA Right △
16. CorrPts △
RZ
18. R is the same distance from the sides of △JKL
17. Transitive Prop
18. Dist Pont To Line
Given: RS ⟂ RO; AE ⟂ AN; OE
≊ NS; RS ≊ AE
Prove: △ROS ≊ △ANE
Hour Glass Proof
[Hour Glass Prf]
Statement
Reason
1. RS ⟂ RO
1. Given
2. AE ⟂ AN
2. Given
3.
ORS is a right
3. ⟂ Lines
4.
NAE is a right
4. ⟂ Lines
5. OE ≊ NS
5. Given
6. OE = NS
6. Segs ≊ IFF Lens=
7. ES = ES
7. Reflexive Prop
8. OE + ES = NS + ES
8. Seg Addition
9. OE + ES = OS
9. Seg Addition
10. NS + ES = NE
10. Seg Addition
11. NE = OS
11. Substitution Prop
12. NE ≊ OS
12. Segs ≊ IFF Lens=
13. RS ≊ AE
13. Given
14. △ROS ≊ △ANE
14. HL Rt
≊
Given: DE = RO; △OXE is
Isosceles
Prove: △DOX ≊ △REX
Pyramid Proof
[Pyramid Prf]
Statement
Reason
1. DE = RO
1. Given
2. DO = DE - OE
2. Seg Subtraction
3. RE = RO - OE
3. Seg Subtraction
4. RE = DE - OE
4. Substitution Prop
5. DO = RE
5. Transitive Prop
6. DO ≊ RE
6. Segs ≊IFF=Len
7. △OXE is isosceles
8. OX ≊ EX
9.
10.
11.
XOE ≊
XEO
DOX and
DOX and
REX and
13.
REX and
10.
DOX ≊
XOE are a linear pair
XOE are supplementary
XEO are a linear pair
XEO are supplementary
REX
11. △ DXO ≊ △REX
7. Given
8. Isosceles △
9. Isos△ SidesIFF
10. Linear Pair
11. Supplementary
12. Linear Pair
13. Supplementary
Supps To ≊ s ≊
SAS △ ≊
Given: IN ≊ IO;
OWN ≊
NKO
Prove: △WOZ ≊ △KNZ
Folded Arms Proof [Folded Arms Prf]
Statement
Reason
1. IN ≊ IO
2. △ION is isosceles
3.
ION ≊
INO
4. ON ≊ ON
5.
OWN ≊
NKO
3. Isos△SidesIFF
5. Given
6. AAS △ ≊
7. Corr Pts ≊△s
7 OW ≊ NK
WZO ≊
2. Isosceles △
4. Reflexive Prop ≊
6. △WON ≊ △KNO
8.
1. Given
KZN
9. △WOZ ≊ △KNZ
8. Vertical
9. AAS △ ≊
s≊
s
Given: BD Bisects EBF
Prove: DE ≊ DF
Two Heights Proof
Statement
Reason
1. BD bisects
2.
EBD ≊
[Two Heights Prf]
EBF
FBD
1. Given
2.
Bisector
3. Let DE be the altitude from D to EB
3. Dist Point To Line
4. DE ⟂ EB
4. LineThruPt ⟂
5.
5. Perp Lines
DEB = 90°
6. △DEB is a right △
6. Right △
7. Let DF be the altitude from D to BF
7. Dist Point To Line
8. DF ⟂ BF
8. LineThruPt ⟂
9.
9. Perp Lines
DFB = 90°
10. △DFB is a right △
10. Right △
11. BD ≊ BD
11. Reflexive Prop ≊
13. DE ≊ DF
13. Corr Pts ≊ △s
12. △EBD ≊ △DFB
12. HA Right △ ≊
Given:
AED ≊
ACD
Prove: j ≊ k
Obtuse Height Proof
[Obtuse Height Prf]
Statement
Reason
1. Construct altitude EQ ⊥ AC
1. LineThruPoint ⊥
2. ⊀EQA is a right ⊀
2. ⊥ Lines
3. Construct altitude JR ⊥ EA
3. LineThruPoint ⊥
4. ⊀CRA is a right ⊀
4. ⊥ Lines
5. ⊀AED ≊ ⊀ACD
5. Given
6. △EAC is isosceles
6. Isos△ SidesIFF s
7. EA ≊ AC
7. Isosceles △
8. ⊀1 ≊ ⊀2
8. Vertical ⊀s ≊
10. ⊀C = ⊀E
10. Corr Pts ≊ △s
12. j ≊ k
12. Corr Pts ≊ △s
9. △EQA ≊ △CRA
11. △CRE ≊ △EQC
9. HA Right △ ≊
11. HA Right △ ≊
Given: AB ⊥ BC; AE ⊥ DE;
≊
2; AB ≊ AE
Prove: AC ≊ AD
Kite Flight Proof
[Kite Flight Prf]
Statement
Reason
1. AB ⟂ BC
1. Given
2.
2. ⟂ Lines
3 is a right
3. AE ⟂ DE
3. Given
4.
4 is a right
4. ⟂ Lines
5.
3=
4
5. Right
6.
3 ≊
4
6.
7.
1 ≊
2
7. Given
8. AB ≊ AE
8. Given
10. AC ≊ AD
10. Corr Pts ≊ △s
9. △ACB ≊ △ADE
s≊
s ≊ IFFMeasures=
9. ASA △ ≊
1
Given: △QRS is isosceles;
RPT ≊
RTP
Prove: PQ ≊ TS
Triangle Hat Proof
Statement
1.
RPT ≊
[△ Hat Prf]
Reason
RTP
1. Given
2. PR ≊ TR
2. Isos△ SidesIFF s
3. PR = TR
3. Segs ≊ IFF Lens=
4. △QRS is isosceles
4. Given
5. QR ≊ SR
5. Isosceles △
6. QR = SR
6. Segs ≊ IFF Lens=
7. PQ + QR = PR
7. Segment Addition
8. TS + SR = TR
8. Segment Addition
9. PQ + QR = TS + SR
9. Transitive Prop
10. PQ + SR = TS + SR
10. Substitution Prop
11. PQ + SR - SR = TS + SR - SR
11. Subtraction Prop
12. PQ = TS
12. Combine Terms
13. PQ ≊ TS
13. Segs ≊ IFF Lens=
Given: BL bisects
QBP; BL ||
JP
Prove: △PBJ is Isosceles
Jungle Gym Proof
Statement
Reason
1. BL bisects
QBP
2. BL || JP
1. Given
2. Given
3. QBL ≊
4. J ≊
[Jungle Gym Prf]
PBL
QBL
5.
J≊
6.
PBL ≊
7.
J≊
8. BP ≊ BJ
PBL
BPJ
BPJ
9. △PBJ is Isosceles
3.
Bisector
4. Corr
s
5. Transitive Prop≊
6. Alt Int
s
7. Transitive Prop≊
8.Isos△ Sides IFF ⊀s
9. Isosceles △
Given: △MNO is isosceles; QM
bisects
NMO
Prove: QM ⟂ NO
Statement
Paper Folding Proof [Paper Folding Prf]
1. △ MNO is isosceles
2. MN ≊ MO
3. QM bisects
4.
MNQ ≊
NMO
OMQ
5. MQ ≊ MQ
6. △NMQ ≊ △OMQ
7.
NQM ≊
OQM
Reason
1. Given
2. Isosceles △s
3. Given
4.
Bisector
5. Reflexive Prop≊
6. SAS △ ≊
7. Corr Pts ≊ △s
8. m NQM = m OQM
8.
9.
9. Linear Pair
NQM and
OQM are a linear pair
s ≊ IFFMeasures=
10. m NQM + m OQM = 180°
10. Linear Pair Supp
11. m NQM + m NQM = 180°
11. Substitution Prop
12. 2m NQM = 180°
12. Combine Terms
13. 2m NQM/2 = 180°/2
13. Division Prop
14. m NQM = 90°
14. Quotient
15.
15. Right
NQM is a right
16. QM ⟂ MO
⁂
16. ⟂ Lines
Given: △MNO is isosceles; QM
bisects
NMO
Prove: QM ⟂ NO
Paper Folding Proof 2
Statement
[Paper Folding Prf 2]
Reason
1. △ MNO is isosceles
1. Given
2. QM bisects
2. Given
NMO
3. MQ is ⟂ Bisector of NO
4. QM ⟂ MO
5.
⁂
3. Isos △
4. ⟂ Lines
Bisector
Given: △MLP is isosceles; N is
the midpoint of MP
Prove: LN ⊥ MP
Statement
Incline Proof
[Incline Prf]
Reason
1. △MLP is isosceles
1. Given
2. N is the midpoint of MP
2. Given
3. LN is the median from vertex L to midpoint N
3. △ Median
4. LN is the ⊥ Bisector of MP
4. Isos△ Median
5. LN ⊥ MP
5. Perp Bisector
Given: AB ≊ CD;
BFA ≊ BFE;
DEC ≊ DEF
Prove: FB ≊ ED
Train Station Proof [Train Station Prf]
Statement
Reason
1. AB ≊ CD
1. Given
2. AC ≊ CA
2. Reflexive Prop ≊
3.
BFA ≊
BFE
3. Given
4. BFA and
BFE are supplementary
4. Supplementary
5.
BFA and
BFE are right
5. ≊ Supp
7.
DEC ≊
8.
DEC and DEF are supplementary
8. Supplementary
9.
DEC and
9. ≊ Supp
6. △ABC ≊ △CDA
10.
BFA ≊
DEF are right
DEC
s Rt
6. HL RIght △ ≊
DEF
11. △BFA ≊ △DEC
12. FB = ED
s
s
s
7. Given
s
s Rt
10. Supplementary
11. AAS △ ≊
12. Corr Pts ≊ △
s
s
s
Given: C is equidistant from A and
B; E is the midpoint of AB
Prove: CE ⟂ AB
Bicycle Rack Proof [BicycleRack Prf]
Statement
Reason
1. C is equidstant from A and B
1. Given
2. E is the midpoint of AB
2. Given
3. CA ≊ CB
3. Segment Midpoint
4. CE ≊ CE
4. Reflexive Prop≊
5. AE ≊ BE
5. Segment Midpoint
6. △CAE ≊ △CBE
CEB
6. SSS △ ≊
7. Corr Pts ≊ △s
7.
CEA ≊
8.
CEA and
CEB form a linear pair
8. Adjacent
9.
CEA and
CEB are supplementary
9. Linear Pair Supp
s
10. m CEA + m CEB = 180°
10. Supplementary
11. m CEA + m CEA = 180°
11. Substitution Prop
12. 2m CEA = 180°
12. Combine Terms
13. 2m CEA/2 = 180°/2
13. Division Prop
14. m CEA = 90°
14. Quotient
15.
15. Right
CEA is a right
16. CE ⟂ AB
16. ⟂ Lines
s
Given: AB = AC; EC = ED;
m B = 55 °; m D = 35 °
Prove: AC ⟂ CE
Statement
Tall Short Proof [Tall Short Prf]
Reason
1. AB = AC
1. Given
2. EC = ED
2. Given
3. m B = 55°
3. Given
4. m D = 35°
4. Given
5.
ACB is isosceles
6.
EDC is isosceles
5. Isosceles △
6. Isosceles △
7. m ACB = m B
7. sides ≊ IFF s ≊
8. m ECD = m D
8. Base
9. m ACB = 55°
9. Subst Prop
10. m ECD = 35°
10. Subst Prop
11. m ACB + m ACE + m ECD = 180°
11. Partition Postulate
12. 55° + m ACE + 35° = 180°
12. Subst Prop
13. 90° + m ACE = 180°
13. Combine Terms
14. 90° + m ACE - 90° = 180° - 90°
14. Subtr Prop
15. m ACE = 90°
15. Combine Terms
16. AC ⟂ CE
16. ⟂ Lines
s≊
Given: △XZY Isosceles; XP the ⊀
bisector of the vertex angle
Prove: XP the ⟂ bisector of the
base
Isosceles △
Bisector ⟂ Bisector Proof [Iso△ Bis⟂BisPrf]
Statement
Reason
1. △XZY is isosceles
2. XP is the
Bisector of the vertex angle,
3.
YXP
PXZ ≊
4. XP ≊ XP
5. △PXZ ≊ △YXP
6.
ZPX ≊
YPX
1. Given
ZXY
2. Given
3.
Bisector
4. Reflexive Prop ≊
5. SAS △ ≊
6. Corr Pts ≊ △s
7. m ZPX = m YPX
7.
8.
8. Linear Pair
ZPX and
YPX are a linear pair
s ≊ IFF=measure
9. m ZPX + m YPX = 180°
9. Linear Pair Supp
10. m ZPX + m ZPX = 180°
10. Substitution Prop
11. 2(m ZPX) = 180°
11. Combine Terms
12. 2(m ZPX)/2 = 180°/2
12. Division Prop
13. m ZPX = 90°
13. Quotient
14. XP ⟂ ZY
14. ⟂ Lines
15. ZP ≊ YP
15. Corr Pts ≊ △s
16. ZP = YP
16.
17. P is the midpoint of ZY
17. Seg Midpoint
18. XP is the ⟂ bisector of ZY
18. ⟂ Bisector
s ≊ IFF=measure
Given: AB ≊ AC; BX bisects B;
CX bisects C
Prove: BX ≊ CX
Concave Proof
[Concave Prf]
Statement
Reason
1. AB ≊ AC
1. Given
2.
B ≊
2. Isos△ SidesIFF s
C
3. m B = m C
3.
s ≊ IFFMeasures=
4. BX bisects
B
4. Given
5. CX bisects
C
5. Given
6.
1 ≊
2
6.
Bisector
7.
3 ≊
4
7.
Bisector
8. m 1 = m 2
8.
s ≊ IFFMeasures=
9. m 3 = m 4
9.
s ≊ IFFMeasures=
10. m A = m 1 + m 2
10.
11. m B = m 3 + m 4
11.
12. m A = m 2 + m 2
12. Substitution Prop
13. m B = m 4 + m 4
13. Substitutuon Prop
14. m A = 2(m 2)
14. Combine Terms
15. m B = 2(m 4)
15. Combine Terms
16. 2(m 2) = 2(m 4)
16. Transitive Prop
17. 2(m 2)/2 = 2(m 4)/2
17. Division Prop
18. m 2 = m 4
18. Quotient
19.
19.
2 ≊
4
20. BX ≊ CX
Addition
Addition
s ≊ IFFMeasures=
20. Isos△ SidesIFF s
Given: IL the ⟂ bisector of HK
Prove:
Arrow Head 1 Proof
Statement
2≊ 4
[ArrowHead 1 Prf]
Reason
1. IL ⟂ the Bisector of HK
1. Given
2. HI = KI
2. ⟂ Bisector
3. KJ = HJ
3. PtOn⊥Bis=Dist
4. IJ = IJ
4. Reflexive Prop
5. △HIJ ≊ △KIJ
6.
1≊
3
7. JL = JL
9. △HIL ≊ △KIL
H≊
6. Corr Pts ≊ △s
7. Reflexive Prop
8. HL = KL
10.
5. SSS △ ≊
K
8. PtOn ⟂ Bis
9. SSS △ ≊
10.Corr Pts ≊ △s
11. m K = m 1 = m 2
11.
Addition
12. m H = m 3 + m 4
12.
Addition
13. m 3 + m 2 = m 3 + m 4
13. Substitution Prop
14. m 3 + m 2 - m 3 = m 3 + m 4 - m 3
14. Subtraction Prop
15. m 2 = m 4
15. Combine Terms
16.
16.
2 ≊
4
s ≊IFF=Measure
Given: IL ⟂ bisector of HK
Prove:
Statement
Arrow Head 2 Proof
2≊ 4
[ArrowHead 2 Prf]
Reason
1. IL ⟂ Bisector of HK
1. Given
2. HL ≊ KL
2. Pt on ⟂Bis IFF EqD
4. IL is the altitude of △HKL
4. △ Altitude
3. △HKL is isosceles
3. Isosceles △
3
5. Isos △ Altitude
6. JL ≊ JL
6. Reflexive Prop ≊
8.
8. CorrPts ≊△s
5.
1≊
7. △ JHL ≊ △ JKL
2≊
4
7. SAS △≊
Given: XZ = XY;
ZXP ≊ YXP
Prove: XP is the ⟂ bisector of
ZY
Angle Bisector Perpendicular Bisector Proof [
Bis ⟂ Bis Prf]
Statement
Reason
1. XZ = XY
1. Given
2.
ZXP ≊
YXP
2. Given
3. XP ≊ XP
3. Reflexive Prop ≊
5. ZP ≊ YP
5. Corr Pts ≊ △s
6. P is the midpoint of ZY
6. Segment Midpoint
4. △XZP ≊ △XYP
7.
ZPX ≊
YPX
4. SAS △ ≊
7. Corr Pts ≊ △s
8. m ZPX + m YPX = 180°
8.
Addition
9. m ZPX + m ZPX = 180°
9. Substitution Prop
10. 2(m ZPX) = 180°
10. Combine Terms
11. 2(m ZPX)/2 = 180°/2
11. Division Prop
12. m ZPX = 90°
12. Quotient
13. XP ⟂ ZY
13. ⟂ Lines
14. XP is the ⟂ bisector of ZY
14. ⟂ Bisector
Given: △ACE with centroid G
Prove: EG = 2/3EB
Statement
Centroid Theorem Proof
[Centroid Thm Prf]
Reason
1. △AEC with centroid G
1. Given
3. Ⓐ△AGE = Ⓐ△EGF + Ⓐ△AGF
3. Partition Postulate
2. Ⓐ△AGB = Ⓐ△AGF = Ⓐ△EGF
4. Ⓐ△AGE = Ⓐ△AGB + Ⓐ△AGB
5. Ⓐ△AGE = 2( Ⓐ△AGB )
6 . Let h be the common height of △AGE and △AGB
7. Ⓐ△AGB = 1/2(GB)h
8. Ⓐ△AGE = 2(1/2(GB)h)
9. Ⓐ△AGE = (GB)h
10. Ⓐ△AGE = 1/2(EG)h
2. ⒶCentroid△s
4. Substitution Prop
5. Combine Terms
6. Substitution Prop
7. △ Area
8. Substitution Prop
9. Product
10. △ Area
11. (GB)h = 1/2(EG)h
11. Transitive Prop
12. (GB)h/h = 1/2(EG)h/h
12. Division Prop
13. GB = 1/2EG
13. Quotient
14. 2GB = 2(1/2EG)
14. Substitution Prop
15. 2GB = EG
15. Product
16. EB = EG + GB
16. Segment Addition
17. EB = 2GB + GB
17. Substitution Prop
18. EB = 3GB
18. Combine Terms
19. EG = 2GB
19. Symmetric Prop
20. EG/EB = 2GB/EB
20. Division Prop
next page
Given: △ACE with centroid G
Prove: EG = 2/3EB
Statement
Centroid Theorem Proof
[Centroid Thm Prf]
Reason
21. (EG/EB)EB = 2/3EB
1. Multiplication Prop
2. EG = 2/3 EB
2. Product
Given: AX bisects TI; IZ bisects AE; XI
≊ ZE; AX and IZ trisect TE;
right
TIN is a
EAR is a right
Prove: IN ≊ AR
Statement
Guitar Strings Proof
[ Guitar Strs Prf]
Reason
1. AX bisects TI
1. Given
2. X is the midpoint of TI
2. Segment Bisector
3. 2(XI) = TI
3. Segment Midpoint
4. 2(XI)/2 = TI/2
4. Division Prop
5. XI = TI/2
5. Quotient
6. IZ bisects AE
6. Given
7. Z is the midpoint of AE
7. Segment Bisector
8. 2(ZE) = AE
8. Segment Midpoint
9. 2(ZE)/2 = AE/2
9. Division Prop
10. ZE = AE/2
10. Quotient
11. XI ≊ ZE
11. Given
12. XI = ZE
12. Segs ≊ IFF Lens=
13. TI/2 = AE/2
13. Substitution Prop
14. 2(TI/2) = 2(AE/2)
14. Multiplication Prop
15. TI = AE
15. Product
16. TI ≊ AE
16. Segs ≊ IFF Lens=
17. AX and IZ trisect TE
17. Given
18. TR ≊ RN ≊ NE
18. Segment Trisector
19. TR = RN = NE
19. Segs ≊ IFF Lens=
20. TR + RN = RN + NE
20. Segment Addition
next page
Given: AX bisects TI; IZ bisects AE;
AX and IZ trisect TE; XI ≊ ZE; TIN is
a right
EAR is a right
Prove: IN ≊ AR
Guitar Strings Proof
[ Guitar Strs Prf]
Statement
Reason
21. TR + RN = TN
21. Segment Addtion
22. RN + NE = RE
22. Segment Addtion
23. TN = RE
23. Transitive Prop
24. TN ≊ RE
24. Segs ≊ IFF Lens=
25. ⊀TIN is a right ⊀
25. Given
26. ⊀EAR is a right ⊀
26. Given
28. IN ≊ AR
28. Corr Pts ≊ △s ≊
27. △TIN ≊ △EAR
27. HL Right △s ≊
Given: △LMN is isosceles; O is the
midpoint of LM; P is the midpoint
of NM; OQ ⊥ LN; PR ⊥ LN
Prove: OQ ≊ PR
Ski Chalet Proof
Statement
1. △LMN is isosceles
[Ski Chalet Prf]
Reason
1. Given
2. LM ≊ MN
2. Isosceles △
3. LM = MN
3. Segs ≊ IFF Lens=
4.
L ≊
N
4. Isos△ SidesIFF s
5. O is the midpoint of LM
5. Given
6. LO ≊ OM
6. Segment Midpoint
7. P is the midpoint of NM
7. Given
8. NP ≊ PM
8. Segment Midpoint
9. LM = LO + OM
9. Segment Addition
10. NM = NP + PM
10. Segment Addition
11. LO + OM = NP + PM
11. Transitive Prop
12. LO + LO = NP + NP
12. Substution Prop
13. 2LO = 2NP
13. Combine Terms
14. 2LO/2 = 2NP/2
14. Division Prop
15. LO = NP
15. Quotient
16. LO ≊ NP
16. Segs ≊ IFF Lens=
17. OQ ⊥ LN
17. Given
18. PR ⊥ LN
18. Given
19.
OQL is a right angle
19. ⊥ Lines 4Rt
20.
PRN is a right angle
20. ⊥ Lines 4Rt
next page
s
s
Given: △LMN is isosceles; O is the
midpoint of LM; P is the midpoint
of MN; DQ ⊥ LN; PR ⊥ LN
Prove: OQ ≊ PR
Statement
Ski Chalet Proof
21.
OQL is a right triangle
22.
PRN is a right triangle
23.
OQL ≊
24. OQ ≊ PR
PRN
[Ski Chalet Prf]
Reason
21. Right △
22. Right △
23. HA Right △ ≊
24. Corr Pts ≊ △s
Given: AB || DC; △AED ≊
△CFB
Prove: △ABE ≊ △CDF
Boxed Triangles Proof
Statement
[Boxed △s Prf]
1. △AED ≊ △CFB
2.
1 ≊
3
3.
5 ≊
6
Reason
1. Given
2. Corr Pts ≊ △s
3. Corr Pts ≊ △s
4. DE ≊ BF
4. Corr Pts ≊ △s
5. DE = BF
5. Segs ≊ IFF Lens=
6. AB || DC
6. Given
7.
7. Alternate Int
7 ≊
8
s
8. EF = FE
8. Reflexive Prop
9. DE + EF = BF + FE
9. Segment Addition
10. DE + EF = DF
10. Segment Addition
11. BF + FE = BE
11. Segment Addition
12. DF = BE
12. Transitive Prop
13.
13.
A=m 1+m 2
Addition
14. m 6 + m A + m 7 = 180°
14. Sum
15.
15.
C= m 3 + m 4
s Of △
Addition
s Of △
16. m 5 + m C + m 8 = 180°
16. Sum
17. m 6 + m B + m 7 = m 5 + m C + m 8
17. Transitive Prop
18. m 6 + m 1 + m 2 + m 7 = m 5 + m 3 + m 4 + m 8
18. Substitution Prop
19. m 6 + m 1 + m 2 + m 7 - m 1 = m 5 + m 1 + m 4 +
m 8-m 1
19. Subtraction Prop
20. m 6 + m 2 + m 7 = m 5 + m 4 + m 8
20. Combine Terms
next page
Given: AB || DC; △AED ≊
△CFB
Prove: △ABE ≊ △CDF
Statement
Boxed Triangles Proof
21. m 5 + m 2 + m 7 = m 5 + m 4 + m 8
[Boxed △s Prf]
Reason
21. Substitution Prop
22. m 5 + m 2 + m 7 - m 5 = m 5 + m 4 + m 8 - m 5 22. Subtraction Prop
23. m 2 + m 7 = m 4 + m 8
23. Combine Terms
24. m 2 + m 7 = m 4 + m 7
24. Substution Prop
25. m 2 + m 7 - m 7 = m 4 + m 7 - m 7
25. SubtractionProp
26.m 2 = m 4
26. Combine Terms
27. △ABE ≊ △CDF
⁂
27. AAS △ ≊
Given: △ ABC is equilateral; P is
the centroid of △ABC
Prove: △AFP ≊ △ADP ≊ BDP ≊
△BEP ≊ △CEP ≊ △CFP
Equilateral Centroid Triangles Proof
Statement
[EquLat Centroid Prf]
Reason
1. P is the centroid of △ABC
1. Given
3. D is the midpoint of AB
3. △ Median
4. AD = DB = 1/2AB
4. Midpoint Thm
6. F is the midpoint of AC
6. △ Median
7. AF = FC = 1/2AC
7. Midpoint Thm
9. E is the midpoint of BC
9. △ Median
10. CE = BE = 1/2BC
10. Midpoint Thm
2. CD is a median of △ABC
5. BF is a median of △ABC
8. AE is a median of △ABC
11. △ABC is equilateral
2. △ Centroid
5. △ Centroid
8. △ Centroid
11. Given
12. AB ≊ AC ≊ BC
12. Equilateral
13. AB = AC = BC
13. Segs ≊ IFF = Length
14. 1/2AB = 1/2AC = 1/2CB
14. Mult Prop
15. AD = DB = AF = FC = CE = BE
15. Transitive Prop
16. AD ≊ DB ≊ AF ≊ FC ≊ CE ≊ BE
16. Segs ≊ IFF = Length
17. AP ≊ AP
17. Reflexive Prop ≊
19. DP ≊ DP
19. Reflexive Prop ≊
18. △AFP ≊ △ADP
20. △ADP ≊ △BDP
next page
18. SSS △ ≊
20. SSS △ ≊
Given: △ ABC is equilateral; P is
the centroid of △ABC
Prove: △AFP ≊ △ADP ≊ BDP ≊
△BEP ≊ △CEP ≊ △CFP
Equilateral Centroid Proof [EquLat Centroid Prf]
Statement
Reason
21. PB ≊ PB
21. Reflexive Prop ≊
23. EP ≊ EP
23. Reflexive Prop ≊
25. CP ≊ CP
25. Reflexive Prop ≊
27. FP ≊ FP
27. Reflexive Prop ≊
22. △BDP ≊ △BEP
24. △BEP ≊ △CEP
26. △CEP ≊ △CFP
28. △CFP ≊ △AFP
29. △AFP ≊ △ADP ≊ △DBP ≊ △BEP ≊ △CEP ≊
△CFP
⁂
22. SSS △ ≊
24. SSS △ ≊
26. SSS △ ≊
28. SSS △ ≊
29. Transitive Prop ≊
Given: m A = 30°;
B is
trisected by BM and BT; C is
trisected by CM and CT
Prove: m M = 80°; m T = 130°
Russian Dolls Proof [△ Trisection Prf]
Statement
Reason
1.
B is trisected by BM and BT
1. Given
2.
ABM
2.
MBT
TBC
Trisector
3. m ABM
MBT
TBC
3. Segs
IFF=Len
4. m ABM
MBT
TBC = m B
4. Partition Postulate
5. m ABM
ABM
ABM = m B
5. Substitution Prop
6. 3m ABM = m B
6. Combine Terms
7. (1/3)3m ABM = (1/3)m B
7. Multiplication Prop
8. m ABM = (1/3)m B
8. Mult Inverse
9. m MBT = m TBC = (1/3)m B
9. Given
10.
10.
11.
C is trisected by CM and CT
ACM
MCT
TCB
Trisector
11. Segs
IFF=Len
12. m ACM
MCT
TCB
12. Partition Postulate
13. m ACM
MCT
TCB = m C
13. Substitution Prop
14. m ACM
ACM
ACM = m C
14. Combine Terms
15. 3m ACM = m C
15. Multiplication Prop
16. (1/3)3m ACM = (1/3)m C
16. Mult Inverse
17. m ACM = (1/3)m C
17.
18. m MCT = m TCB = (1/3)m C
18. Substitution Prop
19. m A = 30°
19. Distributive Prop
20. m A + m ABC + m ACB = 180
20. Given
Addition
Given: m A = 30°;
ABC is
trisected by BM and BT; ACB is
trisected by CM and CT
Prove: m
Statement
M = 80°; m T = 130°
Russian Dolls Proof [Russian Dolls Prf]
Reason
21. 30° + m ABC + m ACB = 180°
21. Substitution Prop
22. 30° + m ABC + m ACB - 30° = 180° - 30°
22. Substitution Prop
23. m ABC + m ACB = 150°
23. Combine Terms
24. m MBC = m MBT + m TBC
24.
25. m MBC = (1/3)m ABC +(1/3) m ABC
25. Substitution Prop
26. m MBC = (2/3)m ABC
26. Distributive Prop
27. m MCB = m MCT + m TCB
27. Substitution Prop
28. m MCB = (1/3)m ACB +(1/3) m ACB
28. Product
29. m MCB = (2/3)m ACB
29. Subtraction Prop
30. m M + m MBC + m
30. Combine Terms
31. m M + (2/3)m
32. m M + (2/3)(m
MCB = 180°
ABC + (2/3)m
ACB = 180
ABC + m ACB) = 180°
Addition
31. Sum
s Of △
32. Substitution Prop
33. m M + (2/3)(150°) = 180°
33. Distributive Prop
34. m M + 100° = 180°
34. Substitution Prop
35. m M + 100° - 100°= 180° - 100°
35. Product
36. m M = 80°
36. Subtraction Prop
37. m T + m CBT + m BCT = 180°
37. CombineTerms
38. m T + 1/3(m ABC) + (1/3)m ACB = 180°
38. Substitution Prop
39. m T + (1/3)(m ABC + m ACB) = 180°
39. Distributive Prop
40. m T + (1/3)(150°) = 180°
40. Substitution Prop
next page
Given: m A = 30°;
ABC is
trisected by BM and BT; ACB is
trisected by CM and CT
Prove: m
Statement
M = 80°; m T = 130°
Russian Dolls Proof [Russian Dolls Prf]
Reason
41. m T + 50° = 180°
21. Product
42. m T + 50° - 50° = 180° - 50°
22. Subtraction Prop
43. m T = 130°
23. Combine Terms