Answer: The answer is (A) complementary angles.
Step-by-step explanation: We are given a figure involving angles 1 and 2 and we are to select the correct relation between these two angles.
We have
[tex]\angle 1+\angle 2+90^\circ=180^\circ,~\textup{measure of a straight angle is 180 degrees}\\\\\Rightarrow \angle 1+\angle 2=180^\circ-90^\circ\\\\\Rightarrow \angle 1+\angle 2=90^\circ.[/tex]
We know that, if the sum of two angles is 90°, then they are said to be complementary angles.
Thus, ∠1 and ∠2 are complementary angles.
Thus., (A) is the correct option.