Let's say point A is (-3,4) and point B is (8,-7).
The x-distance from A to B is -3 to 8. This is equivalent to the expression
. So the x-distance is 11.
The y-distance from A to B is 4 to -7. This is equivalent to the expression
. So the y-distance is 13. We take the absolute value because distance is always positive, and is never negative.
The x- and y-distances create a right triangle. So, we can apply the Pythagoren Theorem:
, where
and
are the shorter sides, and
is the longer side of the triangle.
the x- and y-distances are
and
. We want to find the value of c, since that is the distance between the two points. So, plugging the known values into the Pythagorean Theorem,




So, the distance between the two points is roughly 16.