Surface area

[slim token]

Does anyone know why the flat surface area of a closed cylinder of height h cm and radius r cm is 2pir²cm²?

[hoary zephyr]

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[stone creek]

I mean you can derive it using integrals or riemann sums

Is that what you're asking for?

[slim token]

@stone creek oh someone explained it to me, they said it was because of the two faces at the top and bottom of a cylinder

[stone creek]

Oh wait yeah I see what you mean