Question

The base radius of a cone is \( 7\sqrt{7} \) cm and its height is 21 cm. Find the volume of the cone.

Hint:

Use the formula \( V = \frac{1}{3} \pi r^2 h \) for cones.

Answer 1

Volume of a cone:
\[ V = \frac{1}{3} \pi r^2 h. \] \[ = \frac{1}{3} \pi (7\sqrt{7})^2 \times 21. \] \[ = \frac{1}{3} \pi (49 \times 7) \times 21. \] \[ = \frac{1}{3} \pi (343 \times 21). \] \[ = \frac{1}{3} \pi (7203). \] \[ = 2401\pi \text{ cm}^3. \]