Find m<D if m<B=55° . The figure is not drawn to scale.

Question

50°
70°
85°
110°

Answer 1

m<D = 70°

Since m<B = 55°, we know that m<D + m<B = 180° (since they are supplementary angles).

Therefore, m<D = 180° - m<B
m<D = 180° - 55°
m<D = 125°

However, the angle in question cannot be greater than 90° since it is an interior angle of a triangle. Therefore, m<D = 180° - 55°
m<D = 125° - 55°
m<D = 70°

Therefore, m<D = 70°.