Question

The Surface of a circular swimming pool has an area of 25pi square feet. What's the Circumference?

Answer 1

Answer: Pi = Circumference / Diameter


Pi is often approximated by 3.14 or 22/7, but it has many more digits. It is used in many ways in math.

So, using the definition and multiplying both sides by d, the diameter, we get:

C = ∏d

C = 2∏r [because d=2r where r is the radius of the circle]

Also, the area of the circle is:

A = ∏r2



And, of course, the volume of a cylinder and the volume of a cone and the volume of a sphere and ...(lots more) have Pi (that is, ∏) somewhere in the formula.

In this problem, the area A is 25∏

This means that r2=25 and that r=5.

With r=5, then C=10∏


Step-by-step explanation: I really hope this helps you. :)

Answer 2

Answer: 31.42 feet

Step-by-step explanation: The formulae used for the area of a circle is

A = pi * (radius)^2

where r is the radius of the circle

We know that the area is 25 pi so substitute that into the formula

25pi = pi(r^2)

r^2 = 25

radius = sqrt 25

= 5 ft

si we ignore the negative value of the square root since he radius cannot be negative.

Next we look at the formula for the circumference of a circle

C = pi(d)

= pi *(2r)

= 2(5)(pi)

= 10pi

= 31.42 feet

So the most important part to this question was finding the radius of the circle using the value for the area.