Given the area of a circle is 64(pi) how do you find the radius of the circle?

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Answer 1 · 2017-01-21T15:15:11

See the entire solution process below:

The formula for determining the area of a circle is:

#A = pir^2#

Substituting the value from the problem, #64pi# for #A# and solving for #r# gives:

#64pi = pir^2#

We can divide each side of the equation by #color(red)(pi)#

#(64pi)/color(red)(pi) = (pir^2)/color(red)(pi)#

#(64color(red)(cancel(color(black)(pi))))/cancel(color(red)(pi)) = (color(red)(cancel(color(black)(pi)))r^2)/cancel(color(red)(pi))#

#64 = r^2#

We can now take the square root of each side of the equation to find the radius #r#:

#sqrt(64) = sqrt(r^2)#

#8 = r#

#r = 8#

The radius of the circle is #8#.