Posted by Christopher on Friday, April 12, 2013 at 11:57pm.
Hi Christopher,
Let me explain the method of solving this problem:
Given the area of the ring = 2123 ft^2
The formula for area is pi*r^2, where r is the radius
Therefore,we need to find the r based on the area given
2123 ft^2 = pi*r^2 (work this out using calculator)
r^2 = (2123ft^2)/pi
r = 26 ft
We now know what is r.The formula of circumference of a circle is pi*D,where D is the diameter & we all know that diameter = 2*radius
So, D = 2*26ft = 52 ft
Hence, circumference = pi*D
= pi*52ft
= 163.36 ft
The closest answer is 163 ft.Thats all!
Hope my explanation has made you understand clearly. Good luck :)
Omg I hate clowns haha.
So the area of a circle is A=pi(r^2), and you know that the area of the circle is 2,123 square feet, right? So just set them equal as 2,123=pi(r^2), and solve for r, or the radius.
Just divide both sides by pi and then square root both sides. Now that you have your radius, plug it in to the circumference formula, C=pi(d), d being the diamater.
You would multiply the radius by two, since the radius is half the diameter, and then multiply that by pi.
Hope it works! If you can, try to use the pi button, not just 3.14, since it makes it more accurate.