Question

Determine a medida do ângulo b:

Answer 1

$120 = 6x \\ \frac{120}{6} = x \\ x = 20 \\ \\ 4x + b = 180 \\ 4(20) + b = 180 \\ 80 + b = 180 \\ b = 180 - 80 \\ b = 100$