Given: angle 1 cong angle2

Prove: l ||m

1

l

2

m

3

(1 point)

Proof:

Statements

Reasons

a. angle 1 cong angle2

a. Given

b. angle 2 cong angle3

b.

c. angle 1 cong angle3

c. Transitive Property

d. l ||m

d.

b. Vertical Angles are supplemental

d. If the lines are parallel, then the corresponding angles are congruent

b. Vertical Angles are supplemental

d. If corresponding angles are congruent, then the lines are parallel

b. Vertical Angles are congruent

d. If the lines are parallel., then the corresponding angles are congruent

b. Vertical Angles are congruent

d. If corresponding angles are congruent, then the lines are parallel

Therefore, by the Transitive Property, angle 1 is congruent to angle 3. Since angle 1 and angle 3 are corresponding angles, if the corresponding angles are congruent, then the lines l and m are parallel. Therefore, l || m.