Question

v=pir^2h solve for r

Answer 1

Is that is your form?
\[v=\pi . r^2.h\]

I think this is the volume of a right circular cylinder.

Answer 2

to solve for r:
\[r^2=\frac{ v }{ \pi. h }\]

Answer 3

Take the square root:
\[r=\sqrt{\frac{ v }{ \pi . h }}\]

Answer 4

just put the value of the volume and the height of the cylinder, you get directly the radius of the base (or the top) circle.

Answer 5

@3mar
The poster proably has not learned any methods that would help him with a similar question, from you writing the answer.

It is better to guide him to ht emethod and let him DO the working himself with your help.

Answer 6

Thanks, MrNood.
This requires the asker to be active, not out-of-response.