can you help me find the surface area of a sphere using square units

Question

wyattp17 · Answer

WELCOME TO THE SITE GLAD U COULD JOIN

e.mccormick · Answer

Do you know the formula?  It is related to the area of a great circle of the sphere.

wyattp17 · Answer

OK ALL U NEED IS THE FORMULA

anonymous · Answer

i already tried but it just gives me the wrong answer

e.mccormick · Answer

$4\pi r^2$ got you the wrong answer?  What were the specifics of the question?

wyattp17 · Answer

Surface Area of a Sphere = 4 pi r 2

(r is radius of circle)

anonymous · Answer

the question is "What is the surface area of the sphere shown below with a radius of 7"

wyattp17 · Answer

use the forula i gave u and plug in

anonymous · Answer

i did but all i get is 615 and that isnt on any choices

wyattp17 · Answer

hmmmm

e.mccormick · Answer

Do any of the options have a $\pi$ in them?

anonymous · Answer

yes they do

e.mccormick · Answer

Then just dn't multiply out the $\pi$ part.  Do the numbers only.

anonymous · Answer

thanks i got it :)

whpalmer4 · Answer

usually unless you actually need a number, it's better to leave such answers in the form where they still have things like $\pi$.

e.mccormick · Answer

They call this an exact answer.  The reason why is because $\pi$ can't be given as a number.  3.14 is just close to $\pi$ and is not really all of $\pi$.  A similar thing happens with $\sqrt{2}$.  They call these irrational numbers.  Something to keep in mind for the future!

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