Need help only good answer plis!

A. The angles at the intersection of the two lines can be proven to be congruent and complementary . so they meet at a right angle and the lines are perpendicular.

Step-by-step explanation:

In above question, In order to find whether AB ⊥ CD, Using compass construction & rounder , keep the tip at A and cut arcs at line CD . Follow the same process again with tip at B and cut arcs at line CD . Do this both sides of Line CD i.e. on left side of AB & on right side of AB. Now, join the intersection points of both side arcs which are intersecting each other. Now, to prove both are right angle to each other i.e.  AB ⊥ CD , can be done by proving congruent  and complementary , so they meet at a right angle and Hence , the lines are perpendicular i.e. AB is inclined to CD at angle of 90°.