Remember … The converse of an if/then statement is when you switch around the “if” and “then” parts.

The converse isn’t necessarily true, but …

The converses of the parallel line theorems are true.

So, … If you know that corresponding, alternate interior, or alternate exterior angles are congruent, you automatically know the lines are parallel.

and, … If you know that same-side interior angles are supplementary, you automatically know the lines are parallel.

Are r, s, and t all parallel?

Remember …