Question

an angle is equal to one third of its supplement. find is measure.

Answer 1

let the angle be X
then according to the question ,
X = 1/3 × (180-x)
= 3x = 180-x
=4x = 180
=x = 180/4 = 45....
so the angle is 45 degree

may this will help you

Answer 2

Answer: let the angles be x and 1/3x