In order to know the distance of two points we need to perform the Pythagorean Theorem which is:
This is where a and b are the legs of the triangle and c is the hypotenuse. (This theorem only works in right triangles, triangles with an angle of measure 90°)
In a Cartesian plane the coordinates of two points would be
this would translate the Pythagorean Theorem into:
What we need in the problem is the value of c so we know that
We substitute the values into the Pythagorean Theorem and get:
We know now that the square of the distance of the points is 25 so the distance is either +5 or -5 but since a distance is always positive the distance is 5.