The easiest way to show you how to do this is by working out an
Example: Find the distance between
This is not rocket science.
Step 1: Find the distance between the x-coordinates. We do that by
subtracting one number from the
other and then finding its absolute value.
We have |-2 - (-7)| = |5| = 5
Step 2: Do the same thing with the y-coordinates.
|8 - (-5)| = |13| = 13
The geniuses among you will have noticed that it doesn't matter which
way you subtract the numbers because the absolute value of the answer
would be the same anyway.
Step 3: Square both your answers, add them, and take the
square root. Doing that we get:
52 + 132
= 25 + 169
Taking the square root of 194 and
rounding to 2 decimals places
we get the distance = 13.93
By the way, what you are actually doing is using the
Pythagorean theorem on an
imaginary right-angle triangle with the line joining the two lines being
the hypotenuse. Try it some time - get some
Cartesian graph paper, put your 2 points on the graph, make a right
angle triangle out of it and you'll see what I mean.