Question

A builder wants to install a triangular window with the angles shownin the illustration. What angles will he have to cut to make the windowfit? (Hint: The sum of the angles in a triangle equals 180°.)

Answer 1

The sum of the angles in a triangle is 180

x + ( x+30) + (x+ 30) = 180

Combine like terms

3x + 60 = 180

Subtract 60 from each side

3x + 60 - 60 = 180-60

3x = 120

Divide by 3

3x/3 = 120/3

x = 40

The top angle is 40 degrees

The bottom angles are both the same

x+30

40+30 = 70

The bottom angles are 70 degrees