Question

which angle is complementary to ∠4?

Explanation:

Step1: Recall complementary - angle definition

Two angles are complementary if their sum is 90 degrees.

Step2: Observe the figure

We see that ∠1 is a right - angle (marked by the red square), and ∠1=∠2 + ∠4. So, ∠2+∠4 = 90°.

Answer:

∠2