The four medians of a tetrahedron concur in a point which divides each tetrahedron median in the ratio 1:3, the longer segment being on the side of the vertex of the tetrahedron.
Commandino's Theorem
See also
Bimedian, Tetrahedron, Tetrahedron MedianExplore with Wolfram|Alpha
References
Altshiller-Court, N. "Commandino's Theorem." §170 in Modern Pure Solid Geometry. New York: Chelsea, pp. 51-52, 1979.Commandino, F. Prop. 17 in De centro gravitatis solidorum. p. 21, 1565.Referenced on Wolfram|Alpha
Commandino's TheoremCite this as:
Weisstein, Eric W. "Commandino's Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CommandinosTheorem.html