A right triangle with sides 6 cm, 8 cm and 10 cm is revolved about the side 8 cm. Find the volume and the curved surface of the cone so formed. (Take π = 3.14)

Find what length of canvas 2 m in width is required to make a conical tent 20 m in diameter and 42 m in slant height allowing 10% for folds and the stitching. Also find the cost of the canvas at the rate of ₹80 per meter.

The volume of a right circular cone is 9856 cm³ and the area of its base is 616 cm². Find

(i) the slant height of the cone.

(ii) total surface area of the cone.

The height and the radius of the base of a right circular cone is half the corresponding height and radius of another bigger cone. Find :

(i) the ratio of their volumes.

(ii) the ratio of their lateral surface areas.