The authors want to deduce a brief formulation, and use all-purpose program to get exact result for echelon, rectangle and rotundity cross section.
作者想推导简短的公式，对梯形、矩形和圆形断面采用通用的程序，以得到准确的结果。
2
In Andean popular legend, the Pishtaco attacks wayfarers and slices off their fat, a terrifying fate in a culture that traditionally celebrates rotundity.