Answer:
see explanation
Step-by-step explanation:
Consecutive angles of a parallelogram are supplementary, thus
∠ M + ∠ N = 180 , substitute values
3x + 8x - 40 = 180, that is
11x - 40 = 180 ( add 40 to both sides )
11x = 220 ( divide both sides by 11 )
x = 20
Thus
∠ M = 3x = 3(20) = 60°
∠ N = 8x - 40 = 8(20) - 40 = 160 - 40 = 120°
