Question

In the triangle ABC, find the measure of ∠C.

• A. ${45}^o$
• B. ${35}^o$
• C. ${55}^o$
• D. ${65}^o$

Answer 1

The correct option is A ${45}^o$

Angle sum property: The sum of the measures of the three interior angles of a triangle is 180°.

In the triangle ABC:
m∠A = 45°
m∠B = 90°

So, m∠A + m∠B + m∠C = 180°

∴ m∠A + m∠B = 90° + 45° = 135°

$\text{The third angle is}=180°–135°=45°$


∴ m∠C = 45°