Answer:
∠D = 52º
∠E = 32º
∠F = 96º
Explanation:
the sum of interior angles of a triangle equals 180º
so: (x + 20) + (3x) + 32 = 180
3x + x + 20 + 32 = 180 combine like terms
4x + 52 = 180 subtract 52 from both sides
4x = 128 divide both sides by 4
x = 32
plug x into each angle measure to get them:
∠D = (32) + 20 = 52º
∠E = 32º (given)
∠F = 3(32) = 96º