I certainly enjoy playing with map, compass, and GPS navigation skills, and I'm quite familiar with triangulation using a map and compass to identify one's position on a map (obtain bearings to three landmarks and draw direction lines on a map through the landmarks - location is where the three direction lines intersect).

Can you give more detail on the method you are talking about?? To use the sine function (or any other trig function) you'd need a right angle (90 degrees) for one of the corners and know the length of at least two sides of the triangle.

Ken K.