Question

Find the angle whose supplement is four times its complement.

Answer 1

Let one of the angles be x°

the angle which is 4 times its complement =4x°

therefore,

x + 4x = 90

or, 5x = 90

or, x = 90/5 = 18

so, x = 18° & 4x = 18 ×4 =72°

Hence, the angle which is four times its supplement is 72°.