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hw help please

Please and ty
rounded to nearest meter-
area of circle is 5m squared
find out the circumference.
options:
a) 8
b)5
c)10
d)154
e)212
*m
can someone explain how to get the answer? I get a number around 60...

November 23, 2014

4 Comments • Newest first

simaini

area = pi r^2
5=3.14*r^2
r^2=5/3.14= 1.59
r= sqrt 1.59= 1.26

circumference = 2pi*r= 2*1.26*3.14= 7.9
answer is A.

Reply November 23, 2014
Sojin

Uhh I accidentally did it wrong. It's A lol

Reply November 23, 2014 - edited
PerfectSight

square root of (5 divided by pi) = radius
radius x 2 = diameter
diameter x pi = circumference

Reply November 23, 2014 - edited
halfway

First of all let me just say that I did not come up with this on my own. I'm average at best with math and I've been up for too long so I wasn't about to work out your problem no matter how easy or hard it may be, I simply went on google, found the info on yahoo answers and then posted it here after cleaning it up a little and making it pretty.
Formulas:
A=(pi)(radius)^2
C=(pi)(diameter)

You use the area equation to find the radius. Once you find the radius you double it to get the diameter and plug that into the circumference equation.
1. Divide by pi (this will give you the radius squared)
2. Take that and find the square root (this will give you just the radius)
3. Multiply the radius by 2 to find the diameter.
4. Then multiply the diameter by pi (C=Pi x D) and you will get the circumference.
[i]If this is incorrect I take no credit for it BUT if it's correct I take all credit, ok I am going to sleep now[/i]

Reply November 23, 2014 - edited