Question

If the radii of the circular ends of a bucket 24 cm high are 5 cm and 15 cm respectively, find the surface area of the bucket.

Answer 1

Soln:

Given height of the bucket (h) = 24 cm

Radius of the circular ends of the bucket 5 cm and 15 cm

$r_1=5cm;r_2=15cm$

Let ‘L’ be the slant height of the bucket

$L=\sqrt{(r_1-r_2{)}^2+h^2}$

$=\sqrt{(5-15{)}^2+{24}^2}=\sqrt{100+576}=26cm$

Curved surface area of the bucket

$=\pi (r_1+r_2)L+\pi r_2^2$

$=\pi (5+15)26+\pi {15}^2$

$=\pi (520+225)=745\pi c{m}^2$

Curved surface area of the bucket = $745\pi c{m}^2$