Question

Given: angle 3 and angle 5 are supplementary Prove: Line l is parallel to line m
1 / 2
--------------------------/---------------------------- The transversal should be a diagonal
3/4
/
5 / 6
----------------------/------------------------------
7/8

Answer 1

Since line l and line m are cut by the transversal and angle 3 and 5 are supplementary, that means they are consecutive interior angles which proves that the two lines are parallel.