Question

Find the perimeter (in cm) of a square circumscribing a circle of radius 'a' cm

Answer 1

Side of a square=a+a=2a cm
perimeter of square= 4 x side
                               =4 x 2a
                               =8a cm

Answer 2

given,
radius=a then diameter=2r
=2a cm.
side of square=2a cm
perimeter of square=4×side
=4×2a
=8a cm.