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

48°

Step-by-step explanation:

The sum of the three angles of a right triangle is 180°.

If one angle is 90° and another is 42°, then

90° + 42° + x = 180°

132° + x = 180°

x = 180° - 132° = 48°

The third angle is 48°.