isoperimetric inequality

例句：

1. 1. The shape ofthe circle is determined by its radius andcircumference.
   圆的形状由半径和周长决定。
2. 2. Inmathematics, theisoperimetric inequality isused to study the shape of convex polygons.
   在数学中，等周不等式用于研究凸多边形的形状。
3. 3. The isoperimetric inequalitystates that the perimeter of a polygon is always less than or equal tothe sum of the lengths of allsides.
   等周不等式表明，多边形的周长总是小于或等于所有边长的和。