In the diagram below AM = BM = CM, and angle BMC + A = 210 degrees. Find angle B in degrees.
Angle AMC => x
(180 - x) + 1/2(180 - x) = 210
x = 40
Angle B = x/2
or:
∠BMC : ∠A = 2 : 1
∠A = 210 / 3
