Trigo 2

A triangle's sides are $a, b$ , and $c$ . The medians of the same triangle are $s_a,s_b,s_c$ . $\dfrac{a^2}{s_a}+\dfrac{b^2}{s_b}+\dfrac{c^2}{s_c}\space\huge \square \space\normalsize \dfrac{4}{3}(s_a+s_b+s_c)$ What can we write into the square in the equation above?