Create a polygon from a set of points and then calculating center of gravit

[dikaios]

Dear all,

I have a set of points in a plane. I need to write an algorithm that creates a convex polygon from that set of points (using all points/ no self-intersecting).

Then I need to calculate the centre of gravity of this polygon, taking into account that there are different weights places at each corner.

Any help with these two problems will be highly appreciated!!!

[dikaios]

I found the solution here http://mathworld.wolfram.com/GeometricCentroid.html