在初中平面几何中,已学过有关三角形的共线点有,三角形的三条高交于一点(垂心)、三条中线交于一点(重心)、三边的垂直平分线交于一点(外心)、三内角的平分线交于一点(内心)、一内角的角平分线与另二内角的外角平分线交于一点(傍心、计三个)。本文将再列出并证明几个共线点和共圆点。 In the middle school plane geometry, the collinear points that have been learned about the triangles are: the three high triangles intersect at one point (vertex), the three middle lines intersect at one point (center of gravity), and the three perpendicular bisectors intersect at one point (outer heart). The bisector of the three internal angles intersects at one point (inner heart), the angle bisector of one internal angle and the bisector of the external angles of the other two internal angles intersect at one point (those, three). This article will list and prove several collinear points and co-circles again.