A tiny JavaScript function (104 103 bytes thanks to @tsaniel) calculates the area of a simple, non-self-intersecting polygon. Please note that the calculation is wrong if the polygon is self-intersecting.
Click here to see it in action. Reload the page for an other random example.
Inspired by areaTriangle by @neizod.
That's impossi... oh, wait, it's not. This is funny because I had so many iterations while golfing this down (they are all included here) but the
/2
never moved.