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2021 WSMO Speed Round Problems/Problem 2

Revision as of 10:19, 23 December 2021 by Pinkpig (talk | contribs) (→‎Solution)

Problem

A square with side length of $4$ units is rotated around one of its sides by $90^{\circ}$. If the volume the square sweeps out can be expressed as $m\pi$, find $m$.

Solution

When a square is rotated about one of its sides, then it forms a cylinder. Thus, the answer is $4^3\pi\cdot\frac{90}{360}=16\pi.$ Thus, the answer is $\boxed{16}.$

~pinkpig

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