+9479 | (4, 1) | = | A |
| (4, -7) | = | D |
| (-4, -9) | = | C |
| (4, 2) | = | B |
https://www.desmos.com/calculator/ixbameckcj
Does that help?
+1009 So littraly you are plotting points on your cordinate grid and seeing which one is the closes so you are giving the cordinates of each spot!
Cool...
~Nickolas
+9479 Yep! but be careful because notice that these aren't "regular" coordinates, they're polar coordinates. 
If you want, you can read some more about that here: https://www.mathsisfun.com/polar-cartesian-coordinates.html
