[tex]\bf ~~~~~~~~~~~~\textit{middle point of 2 points }
\\\\
A(\stackrel{x_1}{2m}~,~\stackrel{y_1}{2n})\qquad
C(\stackrel{x_2}{2p}~,~\stackrel{y_2}{2r})
\qquad
% coordinates of midpoint
\left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right)
\\\\\\
\left( \cfrac{2p+2m}{2}~~,~~\cfrac{2r+2n}{2} \right)\implies \left( \cfrac{\underline{2}(p+m)}{\underline{2}}~~,~~\cfrac{\underline{2}(r+n)}{\underline{2}} \right)
\\\\\\
~~~~~~~~[(p+m)~,~(r+n)][/tex]
