Question 1117231
r, radius
4r, height


Base of the prism, area, is {{{(25/360)pi*r^2}}}


Volume given,  {{{(4r)(25/360)pi*r^2=350}}}-------Solve for r, and multiply by 4.


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Skipping a few of the arithmetic steps,
{{{(5/18)pi*r^3=5*7*10}}}

{{{r^3=70*18/pi}}}


{{{r=7.3746}}}

{{{4r=29.5}}}