Question

Fan + Medal

Answer 1

write equatoin for the line and check all the coordinates. then check slopes if they dont lie on same line

Answer 2

see the points here
https://www.desmos.com/calculator/pca6rrpg3w

Answer 3

I used the online slope calculator to find the slope calculator to crank out the slopes of lines AB and CD.

http://www.mathwarehouse.com/calculators/slope-formula-calculator.php

As an example, attached is the output for the slope of line CD. Note that the calculator spews out the slope as well as the formula work. The slope of CD is -2.

If you crank out the slope for line AB, you should get 1/2.

If the slopes of two lines multiply to -1, then the lines are perpendicular.
-2 *( 1/2) = ? From that info, do you see the answer to the posted problem? @CaseyCarns