Question

In $\Delta ABC$, if $AB=AC$ and $\angle B={50}^0$, then $\angle A$ is equal to:

• A. ${40}^0$
• B. ${50}^0$
• C. ${80}^0$
• D. ${130}^0$

Answer 1

The correct option is C ${80}^0$

Given, $AB=AC$ and $\angle B={50}^o$

We have to find $\angle A$

As $\angle B={50}^o$, we have $\angle C={50}^o$

Therefore, $\angle A+\angle B+\angle C={180}^o$

$\Rightarrow 50+50+\angle A={180}^o$

$\Rightarrow 100+\angle A={180}^o$

$\Rightarrow \angle A={80}^o$