Write and solve an equation to find the complement of the angle that measure 42 degree

Complementary angles measures to the sum of 90 degrees. Since there is already an angle of 42 degrees, simply subtract 90 from 42, and you get 48 degrees ...

angle A + angle B = 90 degrees, so

42 + x=90

x=48

Complementary angles add up to 90 degrees.

So we can write:

42 + x = 90

To solve, subtract 42 to both sides:

x = 48

So the complement of a 42 degree angle is a 48 degree angle.