Question:
In ΔABC,if AB = AC and ∠B = 50°, then ∠C is equal to
(a) 40°
(b) 50°
(c) 80°
(d)130°
Solution:
(b) Given, $\triangle A B C$ such that $A B=A C$ and $\angle B=50^{\circ}$.
In $\triangle A B C$, $A B=A C$ [given]
$\Rightarrow \quad \angle C=\angle B \quad$ [anqles opposite to equal sides are equal]
$\Rightarrow \quad \angle C=50^{\circ} \quad\left[\because \angle B=50^{\circ}\right.$ (given)]