I am trying to find an area center of various types of rectagles.

(Center of gravity and midpoint of 4 ertices never work so please think in different way)

Please see this image: http://img22.imageshack.us/img22/7881/rectangles.jpg

I have to position of red dot```
Point vertices[4];
Point areaCenter;
```

I have to find areaCenter so (nearly)

area(areaCenter, vertices[0], vertices[1]) = area(areaCenter, vertices[1], vertices[2]) =

area(areaCenter, vertices[2], vertices[3]) = area(areaCenter, vertices[3], vertices[0])

I tried many different ways to find the mid point but none of them covered every types of rectangles.

Can any1 give me some idea?