Hi Tom

Its not one curve. I extrapolated points on the curve. It was pretty easy after thinking about it a bit. I started at the quadrant of the circle, figured that was 1/4pi, then drew a line tangent 3/4pi long. I repeated the same at 1/8 pi, 1/2 pi, etc. Then I just ran a couple of arcs that hit those points, turned them into a polyline and did an area command.

I ussually let AutoCAD do the heavy lifting when it comes to math, but you have to be careful with it as well. If your Plines don't intersect correctly or if you have arcs that overlap you can get some bad results. Also, ACAD 2000 had a bug in it that messed up the area calculation. They fixed it with service pack 1, but we had been using it for over a year before I discovered the bug and consequently the service pack that fixed it. That's pretty scary considering how often I calculate areas. i learned a couple of lessons, never trust the computer completely and always make sure you are running the latest service pack.

-Steve