Question

In the diagram a semicircle is drawn at one side of an equilateral triangle. If BC is 12 cm, what is the radius of the semicircle?

• A. 6
• B. 3
• C. 9
• D. 12

Answer 1

The correct option is A

6

In the diagram the diameter of the semicircle is the side of the equilateral triangle.

Therefore the radius of the semicircle is = $\frac{d}{2}$ = $\frac{AB}{2}$ = $\frac{BC}{2}$= $\frac{12}{2}$ = 6 cm.