What is the measure of angle B in the triangle?

This triangle is not drawn to scale.

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m∠B= [ ]°

What is the measure of angle B in the triangle This triangle is not drawn to scale Enter your answer in the box mB class=

Respuesta :

40 + 2x - 30 + x + 20 = 180
3x + 30 = 180
3x = 150
  x = 50

m<B = 2x - 30
m<B = 2(50) - 30
m<B = 100 - 30
m<B = 70