If the circumference of a circle and the perimeter of a square are equal then

Let the length of the side of the square be a

Let the radius if circle be r

Perimeter of circle = 2πr

Perimeter of square = 4a

Perimeter of circle = Perimeter of square

2πr = 4a

a = π × r/2

Area of a square = a2

= (π × r/2)2 = π/4 × πr2

Area of circle = πr2

Seeing the co-efficient of πr2

1 > π/4 πr2 > π/4 × πr2

So, (area of the circle) > (area of the square)