Question

The radii of circular ends of a bucket of height 24 cm are 15 cm and 5cm. Find the area of its curved surface

Answer 1

The bucket is in the shape of a frustum.

Curved surface area of a frustum = $\pi (r+R)\sqrt{(R-r)^2 + h^2}$

where R and r are radii of the circular ends

and h is the height of the frustum.

Given :

R = 24 cm

r = 15 cm

h = 5 cm

Substituting the values  in the formula,

Curved surface area of bucket = $\pi (15+24)\sqrt{(24-15)^2+5^2} \\=\pi (39)\sqrt{81+25}\\ =\pi (39) \sqrt{106}\\ =1261.44 cm^2$

Answer 2

Answer:

1634.3 cm² .

Step-by-step explanation:

Let radii be R and r .

It is given R = 15 cm , r = 5 cm and h = 24 cm

We know slant height :

l = [ √ h² + ( R - r )² ]

l = √ 24² + 10²

l = 26 cm .

Now ,

C.S.A. = π ( R + r ) l

= 3.14 × 20 × 26 cm²

= 1634.3 cm² .