Answer:
75 degrees
Explanation:
The shape is a trapezoid. When finding angle measurements in trapezoids:
Angle A + Angle C = 180 degrees
Angle B + Angle D = 180 degrees
Because you need to find the angle of B, we will use Angle B + Angle D = 180 degrees to solve this. Angle D is 105 degrees, so 105 + Angle B = 180. 180-105 equals 75, so angle B is 75 degrees.