Terms for subject Mathematics containing midpoint of a segment

English	Russian
A median of a triangle is a segment from a vertex to the midpoint of the opposite side of the vertex	медиана треугольника
a perpendicular bisector of a segment is a line, ray or another segment that is perpendicular to the segment at its midpoint	срединный перпендикуляр
midpoint of a segment	середина отрезка