A heap of circle is in the form of a cone of diameter $$12\ cm$$, and height $$8\ cm$$. Find its volume? How much canvas cloth is required cover the heap?
Diameter of the conical heap $$=12\ cm$$
Radius of heap $$=\dfrac {12}{2}=6\ m$$
Height of the cone $$=h=8\ m$$
Volume of teh cone $$=V=\dfrac {1}{3}\pi r^2 h$$
$$=\dfrac {1}{3}\times \dfrac {22}{7}\times 6\times 6\times 8=301.71\ m^3$$