Question

If equal angles of an isosceles triangle are $50°$, then the measure of other angles is -

• A. $50°$
• B. $60°$
• C. $70°$
• D. $80°$

Answer 1

The correct option is D

$80°$

By the angle sum property of the triangle, the sum of all the angles will always be equal to $180°$.

Let the third angle of an isosceles triangle be $x.$

Now,

$$\begin{gathered} 50°+50°+x=180° \\ 100°+x=180° \\ x=180°-100° \\ x=80° \end{gathered}$$

Hence, the third angle of the triangle is $80°$.