We deduced equal perimeter inequality of triangle and quadrangle by elementary mathematical methods first and solved general equal perimeter problems by using methods of Fourier series.
本文首先使用初等方法导出三角形与四边形的等周不等式，进而用富里埃级数方法解决了一般等周问题。
2
This paper presents a method to define the quadrangle in the triangle mesh and puts forward a new mesh simplification algorithm based on quadrangle collapse.