A right angle intersects a line at point M. Which statement is true about angles 1 and 2? They are congruent. They are right angles. They are complementary. They are supplementary.

The angle show with the yellow square has a measure of 90°.

Together with angles 1 and 2, they form a straight angle so we have:

∠1+∠2+90°=180°, 

subtracting 90° from both sides we have:

∠1+∠2=90°


If the sum of the measures of 2 angles is 90°, the angles are called complementary.

Since the sum of the measures of angles 1 and 2 is 90°, then these 2 angles are complementary.

Answer: They are complementary