Median of a triangle
= Median of a triangle
= Triangle median
{synonym}
A median joins a <vertex of a polygon> to the midpoint of the opposite side of a <triangle>. For side lengths $a,b,c$, the median to the side of length $c$ has length $m_c=\tfrac12\sqrt{2a^2+2b^2-c^2}$, by <Apollonius's theorem>.