What is the perimeter of a square which circumscribes a circle of radius a cm?
Perimeter of square circumscribes a circle of radius ‘a’.
Side of square = Diameter of circle
Diameter of circle = 2 × radius
So, Side of square = 2a
∵ Perimeter of square = 4 × side
∴ Perimeter of square = 4 × 2a
Hence, the perimeter of the square is 8a.