Surface area of a polygon???

Hello everyone,

Does anyone coould help me with an formula that calculates the surface area of a polygon?

Thanks in advance, sebastien.

Does anyone coould help me with an formula that calculates the surface area of a polygon?
See at
http://pilat.free.fr/english/routines/aire_polygone.htm
or
http://www.learnsvg.com/tutorial3/formula/polygonArea.svg

More details with animation to explain in our tutorial but you have to buy it ....
http://www.learnsvg.com/tutorial3/index.php

Michel

That's ok i found out a formula that seems to work fine.

Thanks Michel.

s?bastien.

Actually, i am using the same formula except that if my result is < 0 i multiply by -1.

Actually, i am using the same formula except that if my result is < 0 i multiply by -1.
I you want that formula run for not crossed polygon, convex or not, and for any choosed point to draw triangles, we keep result for area positive or negative.
If you have only positives areas, your formula run only for convex polygon with choosed point inside your polygon. If you take origin to draw triangles and have more simple formula, you will get false results for many polygons ....

Michel