Question

When a circle is cut in half, that sector is called a ..................

• A. quadrant
• B. semicircle
• C. minor sector
• D. None of these

Answer 1

Answer: (B)

semicircle

A semicircle is a half circle, formed by cutting a whole circle along a diameter line, as shown above. Any diameter of a circle cuts it into two equal semicircles.

The area of a semicircle is half the area of the circle from which it is made.

therefore area of a semicircle = $\frac{\pi R^2}{2}$, where R is the radius.

Option B is the answer.