Question

which angles are complementary to each other?

Explanation:

Step1: Recall complementary - angle definition

Two angles are complementary if their sum is 90 degrees.

Step2: Analyze the given angles

In the figure, assume that there is a right - angle formed. We know that if one angle is part of a right - angle and another angle combines with it to make up the right - angle, they are complementary.
If we assume that ∠1 is a right - angle (90 degrees), and we look at the angles around the intersection point. We can see that ∠4 and ∠3 together form a right - angle. So, ∠4+∠3 = 90 degrees.

Answer:

∠4 and ∠3