The diameters of the lower and upper ends of a bucket in the form of a frustum of a

The diameters of the lower and upper ends of a bucket in the form of a frustum of a cone are 10 cm and 30 cm respectively. If its height is 24 cm, find :

1. The area of the metal sheet used to make the bucket.
2. Why we should avoid the bucket made by ordinary plastic ? [Use π = 3.14]

Answer

Here r₁, = 15 cm, r₂, = 5 cm and h = 24 cm 

Area of metal sheet = CSA of the bucket + area of lower end 

$$ = \pi l(r_1 + r_2) + \pi r_{2}^{2} $$

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

Surface area of metal sheet = 3.14(26 x 20 + 25) cm²

= 1711.3 cm²