taxidistance???
The distance between (8,17) and (11,12) can be found using the Pythagorean Theorem. The vertical distance is 17-12, or 5, and the horiz. distance is 8-11, or -3.
The square of this distance is 5^2 + (-3)^2 = 25 + 9 = 34, and so the distance between these two points is sqrt(34).