What is another way to summarize the outcome of this proof? 1
Given: AB II CD
A
B
4
6
5
Prove: 23 a 26
с
7
8
D
Statement
Reason
1. AB||CD
1. Given
2.23 27
2. Corresponding angles theorem
3. Vertical angles are congruent
3. 27 - 26
4. m23 = m27
m27 = m_6
5. m23 = m26
4. Definition of congruence
5. Substitution
6.23 - 26
6. Definition of congruence
Vertical angles are congruent.
B. If two lines are parallel, then alternate interior angles are
congruent.
C. Corresponding angles theorem.
D. If two lines are parallel, then alternate exterior angles are
congruent.