WEBVTT

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Here is the problem: Find the volume and surface area of a cylinder with radius 4 and height 9.

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Compute the volume (cubic units) and total surface area (square units) of the solid from its dimensions in one length unit.

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Volume: base area times height.

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Surface area: two circles plus the curved side.

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So the answer is Volume equals 144pi approximately 452.3893421 cubic units; surface area equals 104pi approximately 326.725636 square units.

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Volume counts unit cubes inside a solid; surface area counts unit squares needed to wrap it. Doubling every length multiplies volume by 8 and surface area by 4.

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Volume 452.3893421 and surface area 326.725636 are positive.