Find the volume of a right circular cone with : (i) radius 6 cm, heig

1.	Find the volume of a right circular cone with : (i) radius 6 cm, height 7 cm. (ii) radius 3.5 cm, height 12 cm (iii) height 21 cm and slant height 28 cm.
Answer» (i) We have, Radius of cone = 6 cm Height of cone = 7 cm So, volume of cone = \(\frac{1}{3}\)πr²h = 1/3 × 22/7 ×36×7 = 264 cm³ (ii) We have, radius = 3.5 cm height = 12 cm volume of cone = 1/3×22/7×3.5×3.5×12 = 154 cm³ (iii) We have, height = 21 cm s lant height = 28 cm radius r = √(28 2-21 2) = √49×7 = 7√7 cm Volume of cone = 1/3×22/7×7√7×7√7×21 = 7546 cm³

Find the volume of a right circular cone with : (i) radius 6 cm, height 7 cm. (ii) radius 3.5 cm, height 12 cm (iii) height 21 cm and slant height 28 cm.

Answer»

(i) We have,

Radius of cone = 6 cm

Height of cone = 7 cm

So,

volume of cone = \(\frac{1}{3}\)πr²h

= 1/3 × 22/7 ×36×7

= 264 cm³

(ii) We have,

radius = 3.5 cm

height = 12 cm

volume of cone = 1/3×22/7×3.5×3.5×12

= 154 cm³

(iii) We have,

height = 21 cm s

lant height = 28 cm

radius r = √(28 2-21 2)

= √49×7

= 7√7 cm

Volume of cone = 1/3×22/7×7√7×7√7×21

= 7546 cm³