Question

Find the magnitude of an angle which two third of its supplement

Answer 1

Let the angle be x and the supplement angle be 2x/3
x + 2x/3 = 180
5x = 540
x = 108
and thus it's supplement angle = 2x/3
= 2(108)/3 = 216/3 = 72

Answer 2

x+(2/3)x=180
5x=180×3=540
x=108