## Geometry: Common Core (15th Edition)

Use the formula for the area of a rectangle. $A=bh=64\times81=5184$ Since the area of the square is the same, use the formula for the area of a square to find the length of the square's sides. $A=s^2$ $5184=s^2$ $\sqrt{5184}=\sqrt{s^2}$ $72=s$ Use the formula for the perimeter of a square. $P=4s=4(72)=288$