Question

The diameter of the base of a cone is 42 cm and its volume is 12936 cm³. Its height is

विकल्प

• 28 cm

• 21 cm

• 35 cm

• 14 cm

Answer 1

28 cm

Let h be the height of the cone.

Diameter of the cone = 42 cm

Radius of the cone = 21 cm

Then, volume of the cone`= 1/3 pi"r"^2"h"` 

`= 1/3xx22/7xx21xx21xx"h"`

= 22 × 21 × h

Therefore,

22 × 21 × h = 12936

`=> h = ((12936)/(22xx21))`

⇒ h = 28 cm

Hence, the height of the cone is 28 cm.