Question

Angle in a semicircle is:

• A. ${50}^o$
• B. ${90}^o$
• C. ${120}^o$
• D. ${180}^o$

Answer 1

The correct option is B ${90}^o$

The angle at the center $\left(AOB\right)$ is $twice$ the angle at the circumference $\left(APB\right)$. As $AOB$ is ${180}^o$, it follows that $APB$ is ${90}^o$

$AOB$ is the $Diameter$, so it follows that the angle in a semicircle is always a $Rightangle.$