To find the midpoint of a segment (or the midpoint between two points - here the endpoints of the side) we use the midpoint formula. What it comes down to is finding the "average" of the x-coordinate and the "average" of the y-coordinate.
The formula is as follows. The midpoint of the segment with endpoints [tex](x_{1} ,y_{1})[/tex] and [tex](x_{2} ,y_{2})[/tex] is given by [tex]( \frac{x_1+x_2}{2},\frac{y_1+y_2}{2})[/tex]
Let us find the midpoint of side JM. It does not matter which point we designate with the 1s and which we designate with the 2s so let's let J (-7,2) = [tex](x_{1} ,y_{1})[/tex] and M (-6,-4) = [tex](x_{2} ,y_{2})[/tex].
Now we plug these into the formula as follows: [tex]( \frac{-7+-6}{2},\frac{-2+-4}{2}) = ( \frac{-13}{2},\frac{-6}{2})=(-6.5,-3)[/tex]
Let us now find the midpoint of side KL. It does not matter which point we
designate with the 1s and which we designate with the 2s so let's let K (-2,-2) = [tex](x_{1} ,y_{1}) [/tex] and L (-3,-4) = [tex](x_{2} ,y_{2})[/tex]
Now we plug these into the formula as follows: [tex]( \frac{-2+-3}{2},\frac{-2+-4}{2}) = ( \frac{-5}{2},\frac{-6}{2})=(-2.5,-3)[/tex]
