In a cornfield the heap of corns powed are in the form of a cone. Each heap has a diameter of 9 m and height 3.5 m. How much canvas cloth would be required to cover 5 such heaps ?

Question

$\begin{array}{1 1} (a)\; 350\; m^2 \\(b)\; 375\;m^2\\(c)\;400\;m^2 \\ (d)\; 405\;m^2 \end{array}$