Which statement is true about angles 3 and 5?
Two parallel lines are intersected by a third line so that
angles 1 and 5 are congruent.
СТЬ
They are acute.
They are congruent.
They are complementary,
They are supplementary.

The correct statement which is true about angle 3 and 5 is, they are supplementary.

Step-by-step explanation:

Two parallel lines are intersected by a third line so that  angles 1 and 5 are congruent as they are supplementary.Supplementary Angles  are Supplementary when the two angles are add up to 180 degrees. Examples of supplementary angles are 60° and 120°. Two lines are parallel when their slopes are equal. In order to see if the two lines are parallel, we must compare their slopes.A transversal is also known as a line segment, that intersects two or more other lines or also a line segments. When a transversal intersects parallel lines many angles are formed, which are known as congruent.If two parallel lines are intersected by a transversal, the corresponding angles are congruent. If two lines are intersected by a transversal,  the corresponding angles are called as congruent i.e the lines are parallel.