Question 365988
In a triangular cross section of a roof, the seconf angle is twice as large as the first. The third angle is 20 greater than the first angle. how large are the angles?
first angle = x
second angle = 2x
third angle = x+20

Since the sum of 3 angles in a triangle is 180, the equation is
x+2x+(x+20) = 180
         4x = 180 -20
          x = 40

         2x = 2(40) = 80
        
       x+20 = 40+20 = 60

The angles are 40, 80, & 60. 
The sum is 180.