How many different ways can you connect seven noncollinear points?

This is sort of like a probability problem:

Since you have 7 points, you can do

7 x 5 x 4 x 3 x 2 x 1 = 840 ways

The reason why it is 7x5x4x3x2x1 is because

At first you have 7 points to choose from, so that's why you have 7,

Then, you are left with 5 points to choose, it is not 6 because you need 2 points to make a line from the first part.

Then, after you got 2 lines, you are left with 4 points, it's not 3 because for here, you are using the previous point and the new point.