Question

if a square and a circle have the same area, the circle has a smaller perimeter. always true, sometimes true, never true?

Answer 1

area of circle pi *r^2 area of square (with side length a) is a^2
you know that
pi*r^2 = a^2

what can you say then about 2*pi*r (circle perimeter) and 4*a (square perimeter)