Question

Two angles of a triangle are ${30}^o$ and ${80}^o$. Find the third angle.

Answer 1

The sum of the interior angles of a triangle are equal to ${180}^o$.To find the third angle of a triangle when the other two angles are known subtract the number of degrees in the other two angles from ${180}^o$.

Therefore${180}^o-{30}^o-{80}^o={70}^o.$