Fold a piece of squared paper along the diagonal into a triangle, and fold into another triangle.

把一张正方形的纸沿着对角线折成三角形，然后再对折一次。

youdao

Based on the area of a triangle, the paper analyses the interior connection between crank structure and areas of triangle, then provides the design rules for its data.

本文从曲柄滑块机构中各杆件组成的三角形面积观点出发，分析了曲柄滑块机构中各参数与其面积的内在联系，从而得出相关参数的设计准则。

youdao

This paper introduces the method of using a small triangle which is similar to the vision-vanishing point triangle to solve the problem, so that making perspective drawing more rapidly and precisely.

采用一个与视灭三角形相似的小三角形作为绘图辅助，同时结合量点法中的分量点概念进行作图，就可以很好地解决这个难题，而且能更加快速准确地绘制两点透视图。

youdao