[quote]Ok...so how do you calculate the surface area of an irregular shape such as a kite? I can't evenly divide it into two triangles (for the wing tips) and a rectangle (for the middle0[quote]

Yeah there is probably some app now a days to do this, but if you want to do it old school it is not that hard.

1) Get your builders square, a tape measure, and some string.

2) Go out into the back yard and create an X,Y axis with your string and some stakes to hold the string

3) Lay your kite down at the vertex of the X, Y axis

4) Now measure some points on your kites perimeter. Measure the X, and Y.

example: Point A is 6 inches out and 5 inches up. (6,5)

5) The more points the more accurate

6) Get a piece of graph paper and come up with a conversion to use. Example: 1 square equals 1 inch.

7) Plot all your points. Example: point A would be 6 grids in, by 5 grids up

8 ) If you have a drawing curve use that to help connect the dots

9) count all full squares. Those squares completely inside your diagram

10) For the split squares you can be lazy and multiply the total split squares by .5. or it is better to estimate each one. Example: first square is about .25 enclosed, the next is .5 enclosed, the next is .9 enclosed. Sum these up and add to the number found in 9