lengths of triangle medians

By the Apollonius theorem, in any triangle, the $m_a$, $m_b$, $m_c$ of the medians (http://planetmath.org/Median) of opposing the the sides $a$, $b$, $c$, respectively,are

$$m_a=\frac{1}{2}\sqrt{2b^2+2c^2-a^2},$$

$$m_b=\frac{1}{2}\sqrt{2c^2+2a^2-b^2},$$

$$m_c=\frac{1}{2}\sqrt{2a^2+2b^2-c^2}.$$