Hi All,

I need some help on this problem.

Say, in Google Earth or Virtual Earth, we define3 pairof longitude and latitude (or x and y).

We need 3 pair because:

- The first two pair is to define the start and end, therefore, form a direct line.

- Another pair is just a point that is located somewhere else. In most of my cases (99.99%), it is located somewhere between the line (sometimes fall under the path of the line, which means I don't need any further mathematical calculation).

My question is:

How do I find the longitude and latitude intersection in that line, that is a result of the projection from the point?

Thank you in advance for the answer.