How do you solve for r in #V=πr^2h#?

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Answer 1 · 2017-02-10T20:00:20

#r=sqrt(V/(pih))#

Step 1. Divide both sides by #pi#

#V/pi=(cancel(pi)r^2h)/cancel(pi)=r^2h#

Step 2. Divide both sides by #h#

#V/(pih)=(r^2cancel(h))/cancel(h)=r^2#

Step 3. Take #+-sqrt()# both sides

#+-sqrt(V/(pih))=r#

Step 4. Radius, #r#, is not a negative value, so just keep the positive

#r=sqrt(V/(pih))#