Question

5. A building has 14 cylindrical pillars, each of diameter 1 m and height 4.5 m. The curved surface di
the pillars have to be painted leaving 15 cm from top and bottom. Find the cost of painting the pie
at the rate of 25 per m2.​

Answer 1

Answer:

surface area of cylinder= 2πrh = 2×3.14×0.5×4.5= 14.13 m²

surface area of cylinder painted left = 2πrh = 2× 3.14× 0.5×0.15 = 0.471

surface area of cylinder painted = surface area of cylinder - surface area of painted leaving

= 14.13 - 0.471 = 13.7

cost of painting the pillars = 13.7 × 25 = 342.5