Question

an angle is 4÷5of its supplement,what is its magnitude?

Answer 1

Let the angle be x.

Lets its supplementary angle be y.

But x = (4/5) y

x + y = 180

(4/5) y + y = 180

(9/5) y = 180

y = 100

Therefore its magnitude is 80 degrees

-WonderGirl

Answer 2

let the angle be x
supplement = 180°- x
according to q.
x = 4 /5 (180 - x )

x = 4( 36 - x/5 )
x= 144 °- 4x/5
x + 4x /5 =144°
9x / 5 =144°
9x = 720°
x =720/9=80°