Question

A cylinder has radius r and height h how many times greater is the surface area of a cylinder when both dimensions are multiplied by a factor of 2?3?5?10?

Answer 1

Correct answer: 4, 9, 25, 100

Explanation:

Surface area of cylinder A = 2r²π + 2rπ h = 2rπ (r+h)

r₁ = 2r and h₁ = 2h => A₁ = 2 (2r) π (2r+2h) = 2 2rπ 2(r+h) = 4 2rπ (r+h)

A₁ = 4 A

r₁ = 3r and h₁ = 3h => A₁ = 2 (3r) π (3r+3h) = 3 2rπ 3(r+h) = 9 2rπ (r+h)

A₁ = 9 A and so on......

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