Sorry for the deluge of questions lately... - just trying to finally sort the boat out (after two seasons...) ; and this is the place for really good info.!

I've measured my mainsail w/ battens removed. It's :

Luff - 8105mm
Foot- 2113.3mm
Leech (measured all way round head to clue) 8356.6mm

What is the formula to calculate (...checked USSAiling site but can't open the html. file...) area in sq. mtrs. ?( I actually tried what I thought would do this calculation but came way short of 15sq.mtrs. on a main w/ over 250hrs. this is odd...)...

Thank You !!


Paul