Lesson Description Not much of a lesson here, but on a dare from @tracywatanabe, I decided to try to apply the intercept theorem in Google Earth. Trying to perform a compass construction using Google Earth's tools was an interesting exercise. I think it would firm up students' understanding of the theorem or the compass construction. The Kmz download is a tutorial on how to divide a segment to a given ratio. I marked a path to divide into a ratio of 2:4:3. From the starting point, I drew another path at a heading of 0.00 degrees. The ruler tool proved invaluable in that I could use it not only for measuring distance but heading as well (no protractor tool in GE yet). On my second path, I marked distances of 200, 400, and 300 miles. Once I had those, I could find the parallel lines by connecting the two paths' endpoints and then matching the heading for the other parallels. Make sense? I've included notes in the kmz that should explain the whole process. You can find them when you expand the folder in the left sidebar menu.

Of course, applying planar geometry concepts to a sphere is a lesson in itself, but after accomplishing this construction I'm wondering what others can be done and how I'd do them.