Walt wrote:

DSK wrote:

My question defines an area bounded by for sides, a quadrangle, I
suppose I should said "plane geometric shape" rather than "triangle",
sorry for the confusion.

Walt wrote:

OK. If you mean "polygon" please say "polygon".

Isn't a triangle a polygon?

Yes it is.

Anyway, what is the point in using plane geometry to analyse sails? They
are not flat.

Bingo. We've got a winner. Sails aren't triangles. Or Quadralaterals.
Or any other object from plane geometry.


Jumpin' Jiminy, let's see if get a bit more sophomoric! It was merely an
approximation meant to illustrate the thought that if you start with
sail that fits the mast/boat combination correctly, and comes close to
but does not touch the backstay when tacking/jybing, a sail with a
shorter luff that fits the rest of the criteria will have LESS area.

Cheers
Marty