计算测度（长度、面积、体积等）

一个区域的测度对应于曲线的长度、曲面面积和立体体积. 它也可推广到可以测度的零维对象，以及测度是一个广义量的维对象. 对于含不同维数的区域，测度会选取对应于最大维数的量，并以积分形式给出，其中为区域.

曲线长度.

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曲面面积.

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立体体积.

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