Question

write an angle which is equal to twice its complement

Answer 1

Let the angle be x degrees.
complementary angle of x is (90-x)

So x = 2(90-x)
⇒ x = 2×90 - 2×x
⇒ x = 180 - 2x
⇒ x + 2x = 180
⇒ 3x = 180
⇒ x = 180/3
⇒ x = 60°
The angle is 60°.

Check:
complementary angle of 60° = 90-60 = 30°
And 60° is twice is 30°. So Answer is correct.

Answer 2

let the another angle be x
its complement is 2x
complementary angle=  two angles whose sum is 90`
a/q     2x+x=90
        => 3x= 90
             x= 90/3
            ∴x= 30
as first angle is 30
so second angle is 2 x 30= 60
to check, 60+30= 90
and 60 is twice its complement i.e 30