isopermetric polygon

例句：

1. 1. The geometric shapes are all isopermetric triangles.
   这些几何形状都是等面积三角形。
2. 2.The isopermetric ruler is used to measure the length of a line.
   等面积尺用于测量线的长度。
3. 3. The isopermetric theorem states that the area of any polygon is equal to the sum of the areas of its congruent isopermetric triangles.
   等面积定理表明，任何多边形的面积等于与其等面积的等边三角形的面积之和。