Question

If the height of a bucket in the shape of frustum of a cone is 16 cm and the diameters of its two circular ends are 40 cm and 16 cm then its slant height is ______.

विकल्प

• 20 cm

• `12sqrt(5)` cm

• `8sqrt(13)` cm

• 16 cm

Answer 1

If the height of a bucket in the shape of frustum of a cone is 16 cm and the diameters of its two circular ends are 40 cm and 16 cm then its slant height is 20 cm.

Explanation:

We have,

Height of the frustum, h = 16 cm,

Radii of the circular ends, `"R" = 40/2 = 20  "cm" and "r" = 16/2 = 8  "cm"`

Now,

The slant height of the furstum, `l = sqrt(("R" - r)^2+ "h"^2)`

`=sqrt((20-8)^2 + 16^2)`

`=sqrt(12^2+16^2)`

`=sqrt(144+256)`

`=sqrt(400)`

`=20  "cm"`