Question

The height of a cone is 14 cm and its base in 21 cm. Find the curved surface area and the total surface area​

Answer 1

length =12cm, breadth = 8 cm and height = 4.5 cm

∴ Volume of cuboid = l x b x h

= (12 x 8 x 4.5) cm3= 432 cm3

∴ Lateral surface area of a cuboid = 2(l + b) x h

= [2(12 + 8) x 4.5] cm2

= (2 x 20 x 4.5) cm2 = 180 cm2

∴ Total surface area cuboid = 2(lb +b h+ l h)

= 2(12 x 8 + 8 x 4.5 + 12 x 4.5) cm2

= 2(96 +36 +54) cm2

= (2 x186) cm2

= 372 cm2