A point is the intersection of two lines. The distance between two points can be calculated by using the Pythagorean theorem. The problem with finding the center point is that there are many ways to find it, depending on what you are trying to do with it.
For example, if you want to find the center point of a circle, you will need to calculate the diameter and divide it by 2. If you want to find the center point of a triangle, then you need to use its three sides and find its height.