Question

find the angle which is twice its supplement

Answer 1

let one angle be x so another angle is 2x
x+2x=180
3x=180
x=60
angle 120 is the supplement of 60

Answer 2

let the angle be x
therefore its supplement angle=(180-x)
A.T.Q.
x=2(180-x)
=>×=360-2×
=>3×=360
=>×=120

therefore its supplement angle
180-×
180-120
=60


Hope it helps.!.