Question

If the measure of two angles of a triangle are 60° and 30°. Then the measure of the third angle is

• A. ${100}^{\circ }$
• B. ${90}^{\circ }$
• C. ${80}^{\circ }$
• D. ${180}^{\circ }$

Answer 1

The correct option is B ${90}^{\circ }$

Measure of two angles of a triangle are 60° and 30°

Sum of all three angles of triangle = 180°

Therefore, measure of the third angle = 180° - (60° + 30°) = 90°