Median (of a triangle)

A straight line (or its segment contained in the triangle) which joins a vertex of the triangle with the midpoint of the opposite side. The three medians of a triangle intersect at one point, called the centre of gravity, the centroid or the barycentre of the triangle. This point divides each median into two parts with ratio $2:1$ if the first segment is the one that starts at the vertex. The centroid lies on the Euler line.

Comments

J. Hjelmslev has shown that also in hyperbolic geometry (cf. Lobachevskii geometry) the meridians of a triangle intersect at a point.

References

[a1]	H.S.M. Coxeter, "Introduction to geometry" , Wiley (1989)