Question 87935

         Let the measure of the angle be = x 
            supplement of the angle is   = 180-x
            therefore the angle assumed , x = (180-x)-20
                                         x+x= 180-20
                                          2x = 160  x = 160/2 = 80
          required angle = 80degree, supplementry angle = 180-80 = 100 degree
             its complementry angle = 90-80 =10 degree