Question

Assume that the lines DE and XY intersect as in the diagram below. which of the following statements are true

Answer 1

A they are at 90° angles and that is the definition of being perpendicular.

Answer 2

ACD <<<< answer
There are three answers that are true.

B
The problem with B is that complementary angles are 2 angles that are related in such a way that they two angles add to 90o. That means that there are a couple of things wrong. First of all the two angles are on opposite sides of the vertical line XY. That makes them vertically opposite. Secondly, they add up to 180 since both of the are right angles. Third the only point they have in common is the intersection point at A.

The other 3 statements are all correct.

Thanks for revising your question.