SOLUTION: What is the area and the circumference of the circle with a 28yd diameter?

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Question 336371: What is the area and the circumference of the circle with a 28yd diameter?
Found 2 solutions by jim_thompson5910, stanbon:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
If the diameter is d=28, then the radius is r=d%2F2=28%2F2=14 yards. So r=14


Area:

A=pi%2Ar%5E2 Start with the area of a circle formula.


A=pi%2A%2814%29%5E2 Plug in r=14.


A=%283.14159%29%2A%2814%29%5E2 Replace pi with 3.14159 (note: Use more digits of pi to get better accuracy).


A=%283.14159%29%2A%28196%29 Square 14 to get 196.


A=615.75164 Multilpy 3.14159 and 196 to get 615.75164 (this figure is approximate).


A=615.752 Round to the nearest thousandth.


So the area of the circle is roughly 615.752 square yards.

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Circumference:


C=2pi%2Ar Start with the circumference of a circle formula.


C=2pi%2A%2814%29 Plug in r=14.


C=2%283.14159%29%2A%2814%29 Replace pi with 3.14159 (note: Use more digits of pi to get better accuracy).


C=6.28318%2A%2814%29 Multiply 2 and 3.14159 to get 6.28318.


C=87.96452 Multiply 6.28318 and 14 to get 87.96452.


So the circumference of a circle with a radius of 14 yards is about 87.96452 yards.


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my website.

Jim

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
What is the area and the circumference of the circle with a 28yd diameter?
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Perimeter = (pi)d = 28(pi) = 87.96.. yrds
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Area = (pi)r^2 = (pi)*14^2 = 196pi = 615.75 sq. yds
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Cheers,
stan H.