Question

The height and the slant height of a cone are 21 cm and 28 CM respectively. Find the volume of the cone.​

Answer 1

Answer:

If the height and the slant height of a cone are 21 cm and 28 CM respectively then the volume of the cone is 7,546 cubic cm.

Step-by-step explanation:

Given

Slant height (l) = 28 cm

Height of the cone = h = 21 cm

Find: Volume of the cone  

Formula:

Volume of the cone $= \frac{1}{3} \pi r^2 h$

If the radius of cone = r cm

then

$l^2 = h^2 + r^2\\r^2 = l^2 - h^2\\=(28)^2 - (21)^2\\= (28-21)(28+21)\\= 7 \times 49\\r = 7 \sqrt{7} cm$

Volume of the cone $= \frac{1}{3} \pi r^2 h$

$= \frac{1}{3}\frac{22}{7} (7 \sqrt{7} )^2 (21)\\=\frac{1}{3} \times 22 \times 49 \times 7 \times 3\\= 22 \times 49 \times 7\\= 7,546 cm^3$

So, the volume of the cone is 7546 cubic cm.