Proving Lines Perpendicular

Page 4

To prove lines perpendicular:

1 2

Prove:

Given: 21

s

t

ts Statement Reason

1. Given

2. Two intersecting lines that form congruent adjacent angles are perpendicular

21 1.

2. ts

Statement

1. Given

Reason

1. Given

Statement Reason

Pg. 4 #1

41 1.

3421 .3 3. Addition Postulate

4. Partition Postulate

5. Substitution PostulateBDCADC .5

32 2. 1. Given

2. Given

BDCADC

34 21 .4

ABCD .6 6. Two intersecting lines that form congruent adjacent angles are perpendicular

Statement Reason

1. Given

2. Given

Pg. 4 #2

BCAC 1.

DBACD CΔΔ .5 SASSAS .5

21 .3 3. An angle bisector divides an angle into two congruent parts

ACBCD bisects 2.

CDCD .4 4. Reflexive postulate

BDCADC .6 6. CPCTC

ABCD .7 7. Two intersecting lines that form congruent adjacent angles are perpendicular

1 2

Statement Reason

1. Given

2. Given

Pg. 4 #3

PSPR 1.

SPQRPQ ΔΔ .4 SSSSSS .4

43 .8

PQPQ .3 3. Reflexive postulate

21 .5 5. CPCTC

RSPQ .9 9. Two intersecting lines that form congruent adjacent angles are perpendicular

QSQR 2.

8. CPCTC

E

1 2

SPERPE ΔΔ .7 SASSAS .7 PEPE .6 6. Reflexive postulate

4 3