Question

Find the curved surface area of a bucket having radius 28cm and 7cm and slant height 45cm.

Answer 1

Given: R(big radius)=28cm and r(small radius)=7cm and slant height(l)=45cm.

Csa of frustum(bucket)= πl(R+r)

=(22/7)45[28+7]

=(22/7)45[35]

=(22*45)35/7

=990*5

=4950 cm.sq

Answer 2

(GIVEN)

Radius = 28 cm(R) and 7 cm(r)

Slant height = 45 cm(l)

π = 22/7 or 3.14

Formula of the curved surface area(frustum because of the shape of the bucket) = πl(R+r)

To prove:

hence,πl(R+r) = (22/7)45(28+7)

                      =(22/7)45(35)

                      =22/7 × 45 × 35

                      =22×45×35/7

                      =34,650/7

                      =4950 cm2

Answer: 4950 cm2(cm sq)