Question

In the given figure, ABCD is a parallelogram in which $\angle ={70}^0.$ Calculate $\angle B,\angle C$ and $\angle D.$

Answer 1

In a parallelogram, opposite angles are always equal.

$\Rightarrow \angle A=\angle C$ and $\angle B=\angle D$

as $\angle A={70}^o\Rightarrow \angle C={70}^o$

Also $\angle A+\angle B+\angle C+\angle D={360}^o$

$\Rightarrow \angle B+\angle D={360}^o-{140}^o$

$\Rightarrow 2\angle B={220}^o$

$\Rightarrow \angle B={110}^o$

$\Rightarrow D={110}^o$