Question

Find the circumference of a circle whose area is 452.16 square meters. (Use 3.1416 as the value of .)

Answer 1

1) The area of a circle is given by

$A=\pi r^2$

where r is the radius of the circle. In this problem, we are told that the area is

$A=452.16 m^2$

so we can rearrange the previous equation to calculate the radius:

$r=\sqrt{\frac{A}{\pi}}=\sqrt{\frac{452.16 m^2}{3.1416}}=12.0 m$

And now we can find the circumference, by using the formula:

$c=2 \pi r=2 \pi (12.0 m)=75.3984 m$

Therefore, the correct answer is D. 75.3984 meters.

2) The volume of a cube is given by:

$V=L^3$

where L is the length of the edge. In this problem, L=6 cm, therefore the volume of the cube is

$V=L^3=(6 cm)^3=216 cm^3$

and so, the correct answer is A. 216 cu. cm.