The measurement of one angle of a right triangle is 42°. What is the measurement of the missing angle?

All triangles have 3 angles that add up to 180 degrees.

All right angle triangles have a 90 degree angle.

You have two angles, 90 and 42.

To find the last one, add 90 and 42. Then subtract that from 180 degrees.

90+42=132

180-132=48

Therefore, the missing angle is 48 degrees.