Question

$AB$ is the diameter of a circle, center $C$. $P$ is a point on the circumference. Calculate the angle $a^o$.

• A. ${90}^o$
• B. ${43}^o$
• C. ${34}^o$
• D. ${138}^o$

Answer 1

The correct option is B ${43}^o$

All inscribed angles subtended by a semicircle are right angles ${90}^o$
So, the sum of the triangle, $180=47+90+a^o$
$180-137=a^o$
$\angle a^o={43}^o$