Sorry, my question wasn't clear.

I need a drawing program or something.... (I do numbers, not graphics - see other thread )

The answer to your question will depend on the shape of the trailing edge of the wing that the aileron is mated (hinged) to.

For example, if it is flat, then you must angle the leading edge of the aileron.

If you have nice circular rounded leading edge then it won't rotate freely against the flat trailing edge of the wing when hinged. The rounded edge will *roll* along the flat edge.... yes... but won't rotate free when hinged.