Question

ABCD is a parallelogram and $\angle A={75}^{\circ }.$ Find $\angle B$.

• A. ${45}^{\circ }$
• B. ${105}^{\circ }$
• C. ${60}^{\circ }$
• D. ${75}^{\circ }$

Answer 1

The correct option is B ${105}^{\circ }$

In a parallelogram ABCD,
$\because$ The sum of adjacent angles of a parallelogram is equal to ${180}^{\circ }.$
$\therefore \angle A+\angle B=180°$
$\Rightarrow \angle B={180}^{\circ }-\angle A$
$={180}^{\circ }-75°$
$={105}^{\circ }$