Left Panel Interactive

Statements

Reasons

1. #&\overline{\sf AB}#& || #&\overline{\sf CD}#&

1. given

2. m∠1 = m∠2

2. given

3. ∠1 and ∠3 are supplements.

3. same side interior angles theorem

4. m∠1 + m∠3 = 180

4. def. of supplementary angles

5. m∠2 + m∠3 = 180

5. substitution property

6. ∠2 and ∠3 are supplements.

6. def. of supplementary angles

7. #&\overline{\sf AC}#& || #&\overline{\sf BD}#&

7. converse of same side interior angles theorem