Volume of a Right Circular Cone = ${1/3}πr^2h$ 
where $r$ is the base radius and $h$ is the height of the cone.
EXERCISE 13.7
Assume π = $22/7$ unless stated otherwise
1. Find the volume of the right circular cone with
(i) radius 6 cm, height 7 cm (ii) radius 3.5 cm, height 12 cm

2. Find the capacity in litres of a conical vessel with
(i) radius 7 cm, slant height 25 cm (ii) height 12 cm, slant height 13 cm

3. The height of a cone is 15 cm. If its volume is 1570 cm3, find the radius of the base.
(Use π = 3.14)

4. If the volume of a right circular cone of height 9 cm is 48π $cm^3$, find the diameter of its base.

5. A conical pit of top diameter 3.5 m is 12 m deep. What is its capacity in kilolitres?

6. The volume of a right circular cone is 9856 $cm^3$. If the diameter of the base is 28 cm,find
(i) height of the cone 
(ii) slant height of the cone
(iii) curved surface area of the cone

7. A right triangle ABC with sides 5 cm, 12 cm and 13 cm is revolved about the side 12 cm.
Find the volume of the solid so obtained.

8. If the triangle ABC in the Question 7 above is revolved about the side 5 cm, then find
the volume of the solid so obtained. Find also the ratio of the volumes of the two
solids obtained in Questions 7 and 8.

9. A heap of wheat is in the form of a cone whose diameter is 10.5 m and height is 3 m.
Find its volume. The heap is to be covered by canvas to protect it from rain. Find the
area of the canvas required.