Question

Suppose that you needed to make a pen for some small animals. You have 12 m of fencing. You decide to make a circular pen, because if you wish to enclose an area using a given length of fencing, then a circular fence encloses a larger area than a fence of any other shape. What is the radius r of the pen? Express your answer in meters to four significant figures.

Answer 1

Answer:

1.909 m

Explanation:

Length of fence = 12 m

r = Radius of circle made by the provided fence

Cirumference of a circle is given by

$C=2\pi r$

The circumference of the circle will be equal to the length of the fence

$2\pi r=12$

$\\\Rightarrow r=\dfrac{12}{2\pi}$

$\\\Rightarrow r=1.909\ m$

The radius of the fence is 1.909 m