Question

a metal pipe is 82 cm long the inner diameter is 12 cm and Outer diameter is 16 cm find its total surface area​

Answer 1

Answer:

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Step-by-step explanation:

h= 82 cm

Let inner diameter be, d= 12 cm

Therefore, r= 6 cm

Let outer diameter be, D= 16 cm

therefore, R= 8 cm

TSA of cylinder= 2 pi (R-r) [(R-r)+h]

= 2 x 22/7 x (8-6) [(8-6)+82]

= 2 x 22/7 x 2 [2+82]

= 4 x 22/7 x 84

= 4 x 22 x 14

= 1232 sq. cm

Answer 2

Height = 82 cm

Inner diameter = 12 cm

radius = 12/2 = 6 cm

Inner total surface area = 2*22/7*6(82+6) = 3318.8

Outer diameter = 16 cm

radius =16/2 = 8 cm

Outer total surface area = 2*22/7*8(82+8) = 4525.7

Outer base area = 22/7*8^2 = 201.1

Inner base area = 22/7*6^2 = 113.1

Area of the thickness = 201.1 - 113.1 = 88

Total area of thickness = 88*2 = 176

Total surface area = 3318.8 + 4525.7 + 176 = 8020.5