Question

a cylindrical pillar has a diameter of 56 cm and is of 35 m high there are 16 pillars around the building find the cost of the painting the curved surface area of all the pillars at the rate of 5.50 rs per 1 m.sq​

Answer 1

$<b><i>$Given,

A cylindrical pillar, diameter = 56cm = 0.56m

i.e. r = 0.28cm

Height h = 35m

Number of pillars n = 16

Curved surface area of a pillar = 2πrh

= 2 × 3.14 × 0.28 × 35

= 61.54cmCurved surface area of 16 pillars = 16 × 61.54

= 984.64cm2

Cost of painting = 5.5 × 984.64

= 5415.52

Answer 2

Answer:

Rs 5415.872

Step-by-step explanation:

The diameter of the cylindrical tower = 56 cm .

Radius =  diameter / 2 .

➡ Radius = 56 cm / 2

➡ Radius = 28 cm .

The curved surface area refers to the area surrounding the pillar .

The area of cross section is nothing but a circle . Hence the perimeter of the circle and the height are multiplied .

Curved surface area = 2 π r h

h = 35 m

r = 28 cm

➡ r = 0.28 m

There are 16 pillars . So multiply the whole thing with 16 .

Total curved surface area

➡ 16 × 0.28 m × 35 m × 2 × 3.14

➡ 9.8 × 2 × 3.14 × 16

➡ 61.544 × 16 m²

➡ 984.704 m²

Since Rs 5.5 is for 1 m² , then :

Cost = Rs 5.5 × 984.704 m²

➡ Rs 5415.872