Question

If perimeter of the circle is $12\pi$ then find the perimeter of semicircle and determine which of the shape has smaller perimeter.

• A. Circle
• B. Semicircle
• C. Both are equal
• D. Can't determine

Answer 1

The correct option is B Semicircle

Perimeter of circle $=$ $2\times$$\pi$$\times r$

$2\times$$\pi$$\times r$ $=$ $12$$\times$$\pi$

$r=6$

Perimeter of semicircle $=$ $\pi$$r$$+$$2r$ $=$$6\pi$$+12$

perimeter of circle is more than semi circle.

Hence, Option B is correct.