Question

A cylindrical pillar is 70 cm in diameter and 2m in height .Find the cost of painting the curved surface of the pillar at the rate of Rs 16 per m/square​

Answer 1

Given,

A cylindrical pillar is 70 cm in diameter and 2m in height.

To Find,

The cost of painting the curved surface of the pillar at the rate of Rs 16 per m².

Solution,

Height of the cylindrical pillar = 2m

Diameter of the pillar = 70 cm

∴ Radius of the pillar = $\dfrac{70}{2}$ = 35 cm = 0.35m

CSA of cylinder =  2πrh

= $2\times\:\dfrac{22}{7}\times\:2\times\:0.35$

= 44m²

Rate of painting an area of 1m² = Rs 16

∴ Rate of painting an area of 44m² = 16 x 44

= Rs 704

Therefore the cost of painting the CSA of the pillar is Rs 704.

Surface Areas and Volume of Cylinder

→ CSA = 2πrh

→ TSA = 2πr (r + h)

→ Volume = πr²h

→ A cylinder is a 3D solid figure that has 2 parallel bases that is connected by a straight curved surface. It has a total of 3 faces.