Question

the magnitude of an angle which is 2/3of it's supplement​

Answer 1

Let the first angle be `x`

Then the other angle will be 2/3 of x = 2x/3

According to the Q

⇒x + 2x/3 = 180    [supplementary]

⇒(3x+2x)/3 = 180

⇒5x = 180 ×3

⇒x = 540/5

∴x= 108°

∴The required angle = 2x/3

                                 = 2(108)/3 

                                 = 216/3

                                 = 72°.