Triangle ACD and Triangle CAB are the same or equivalent, and side AD is parallel to side BC. Find ∠B.
A triangle is 180°. To find x you can add all of the angles together and set it equal to 180°
37° + 3x° + (2x+8)° = 180°
Subtract 37° on both sides
3x° + (2x+8)° = 143°
3x° + 2x° + 8° = 143°
5x° = 135°
x = 27°
Since ∠D=∠B
3(27) = ∠B
81° = ∠B