<PRE><B>Question 996793</B>
calculate a diameter of a solid cylinder which has height of 82cm and total surface area of 2square meter
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Total area = lateral area + 2 ends
= {{{2pi*r*h + 2pi*r^2}}}
2 sq meters = 20000 sq cms
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{{{2pi*r*h + 2pi*r^2 = 20000}}}
{{{pi*r*h + pi*r^2 = 10000}}}
{{{82r + r^2 = 10000/pi}}}
{{{r^2 + 82r - 10000/pi = 0}}}
*[invoke solve_quadratic_equation 1,82,-10000/pi]
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Ignore the negative solution
r = 28.743 cm
d = 57.486 cm
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