Annali di Matematica Pura ed Applicata ( IF 1.0 ) Pub Date : 2021-02-18 , DOI: 10.1007/s10231-021-01075-9 Shigehiro Sakata
We analytically characterize equilateral triangles. Our characterization includes the classically well-known characterizations: for a given triangle in the Euclidean plane, if the centroid and incenter of the triangle coincide, then the triangle must be equilateral; for a given triangle in the Euclidean plane, if the centroid and circumcenter of the triangle coincide, then the triangle must be equilateral. In our characterization, we consider the convolution of a radially symmetric function and the characteristic function of a triangle. The centroid, incenter and circumcenter of a triangle are described in terms of critical points of such a convolution.
中文翻译:
等边三角形的解析表征
我们分析性地刻画了等边三角形。我们的表征包括经典的众所周知的表征:对于在欧几里得平面中的给定三角形,如果三角形的质心和中心重合,则三角形必须等边;对于欧几里得平面中的给定三角形,如果三角形的质心和外心重合,则三角形必须是等边的。在表征中,我们考虑了径向对称函数和三角形特征函数的卷积。根据这种卷积的临界点描述了三角形的质心,内心和外心。