Given the coordinates;

The slope m of the line MN is;


The slope of a line parallel to the line MN must have a slope equal to line MN, that is;

The slope of a line perpendicular to line MN has a slope of negative reciprocal of line MN, that is;

Using the distance formula to find the length of MN, the formula is given as;
![D=\sqrt[]{(y_2-y_1)^2+(x_2-x_1)^2}](https://img.qammunity.org/2023/formulas/mathematics/college/bn18956xdzpj56va064oiuu2531qoyd8xa.png)
![\begin{gathered} \text{Where x}_1=4,y_1=-4,x_2=2,y_2=0 \\ |MN|=\sqrt[]{(0-(-4)^2+(2-4)^2} \\ |MN|=\sqrt[]{16+4} \\ |MN|=\sqrt[]{20} \\ |MN|=4.5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/td4za2ws20yia28jl2bmjm5gssfntdss5m.png)