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

Refer to the attachment

Answer 2

Step-by-step explanation:

Given :-

The height and the slant height of a cone are 21 cm and 28 cm respectively.

To find:-

Find the volume of the cone ?

Solution:-

Given that :

Height of the cone = 21 cm

Slant height of the cone = 28 cm

We know that

Slant height of the cone =√(h^2+r^2) units

=>28 =√(21^2+r^2)

=> 28^2 = 21^2+r^2

=> 28^2-21^2 = r^2

=> r^2 = (28+21)(28-21)

=>r^2 = (49)(7)

=> r=√(49×7)

=>r =7√7 cm

Radius of the cone = 7√7 cm

Now,

The volume of a cone = (1/3)πr^2h cubic units

=> (1/3)×(22/7)×(7√7)^2×21 cubic cm

=> (1/3)×(22/7)×(343)×21

=> (1×22×343×21)/(3×7)

=>(22×343)

=>7546 cubic cm

Answer:-

The volume of the given cone is 7546 cubic cm

Used formulae:-

• Slant height of the cone =√(h^2+r^2) units

• The volume of a cone = (1/3)πr^2h cubic units

• π=22/7

• r = radius

• h = height

• l = slant height