Question

find the curved surface area of 12 cylindrical pillars of radius 28cm and height 4m and also find out of painting of all pillars at the rate of rupee 8 per m sq.

Answer 1

curved surface area = 2 × pi × r × h = 2 × 22/7 × 0.28 × 4 = 7.04 m2
curved area of 12 such cylinders = 7.04 × 12 = 84.48 m2
Cost = rs 84.48 × 8 = rs 675.84

COST IS RS 675.84 AND CURVED SURFACE AREA IS 84.48 CM2

Answer 2

Answer:

Given,

r =28cm

= 28/100m

=0.28m

h =4m

≈ CSA of a cylinder = 2×22/7×r×h

= 2×22/7×0.28×4

=176/25

= 7.04 m

≈ CSA of 12 cylinder = 7.04×12

= 84.48 m

≈ At rate, painting of pillars = ₹ 8 per m sq. unit

= ₹ 8×84.48 m

= ₹ 675.84