The diagram represents a large glass cone of height 12 cm and base diameter 18 cm. The large cone is made by placing a small cone P of height 8 cm and base diameter 12 cm on top of a frustum Q.

$$Volume\; of\; cone=\frac{1}{3}\pi r^{2}h$$ $$Curved\; surface\; area\; of\; cone=\pi rl$$