Question

find the measure of an angle which is four times its complement​

Answer 1

sum of 2 complementary angles=90°.
let the number is x
the other angle is 4x.
a.q. x+4x=90°
=5x=90°
=x=90°÷5
=x=18°
therefore 1 angle is 18°and other is72°.

Answer 2

Let one angle be x

then,

x+4x=90

5x=90

x= 90/5

= 18

so 18 is the measure of an angle which is four times it's complement