Question

Can someone explain why A is the right answer to this question? I'm unsure of how to work out this problem.

Answer 1

So firstly, we have to find the radius of the circular garden before finding the circumference (the amount of fencing needed to surround the garden). To find the radius, use the area formula ($A=\pi r^2$), plug in the area of the garden (36 ft^2) and solve for r as such:

$36=\pi r^2\\ \frac{36}{\pi}=r^2\\ \frac{\sqrt{36}}{\sqrt{\pi}}=r\\ \frac{6}{\sqrt{\pi}}=r$

So that we know the radius, plug that into the circumference equation ($C=2\pi r$) to solve:

$C=2\pi*\frac{6}{\sqrt{\pi}}\\ C=\frac{12\pi}{\sqrt{\pi}}\\ C=12\sqrt{\pi}$

Your answer is A. 12√π.