Question

In a building there are 36 cylindrical pillars. The radius of each pillar is 21cm and height is 4metre.

Find the total cost of painting the curved surface area of all the pilars at the rate of Rs 12/m².​

Answer 1

the Radius of pillar (r) = 21 cm or 0.21 cm

and height of pillar(h) = 4 m

Curved surface area of the pillar = 2πrh

= 2×22/7×0.21×4

= 13.2m^

Area required for such 36 pillar =13.2 ×36

= 475.2 m^

the cost of painting the curved surface

area of all pillars at the rate of Rs 12/m²

=475.2× 12 = Rs. 5,702.4