Question

Consider the figure:

If BC = AC and angle ACB = 30^o, then find the value of $\angle A$ and $\angle B$.

• A. ${75}^{\circ }$
• B. ${150}^{\circ }$
• C. ${65}^{\circ }$
• D. ${70}^{\circ }$

Answer 1

The correct option is A ${75}^{\circ }$

Given $\angle ACB={30}^o$ and BC = AC,
Therefore $\angle A=\angle B$ (base angles are equal in an isosceles triangle)

$\therefore$ By angle sum property of triangle,
$\angle A=\angle B=\frac{{180}^o-{30}^o}{2}$
$=\frac{150}{2}={75}^o$