question_answer

The perimeter of a square circumscribing a circle of radius a cm is equal to ............ cm.

A) 8a

B) 4a

C) 2a

D) \[\frac{a}{2}\]

Correct Answer: A

Solution :

Given, radius of circle, r = a cm

\[\therefore\] Diameter of circle, \[d=2\times\] Radius = 2a cm

\[\therefore\] Side of a square = Diameter of circle

= 2a cm

\[\therefore\] Perimeter of a square  \[=4\times\](Side) \[=4\times 2a\]

\[=8a\,cm\]