The measure of an angle is 82 °. What is the measure of its complementary angle?

8 degrees (see explanation below)

Step-by-step explanation:

A complimentary angle is when 2 angles are added together to make a 90 degree angle. So if the measure of the current angle is 82, then the other measure is 8.

Draw the diagram shown below to illustrate the problem.

Let x =  length of a side of the enclosing square.

The area of the triangle is 21 cm², therefore
(1/2)*x*6 = 21
3x = 21
x = 7 cm

The area of the square is
7*7 = 49 cm²

The area of the shaded region is
49 - 21 = 28 cm²

28 cm²