Radian measure

Today we reviewed the unit circle and developed a working definition of a radian. I may be posting some notes later on this if you require them, but the module isn't too bad at explaining it (although I think the picture at the bottom of the title page for lesson 4 explains it all). I really need people to be able to ask questions on lesson 3 by tomorrow so that I can show some examples from lesson 4 and get on to some theory for lesson 5.

Please keep in mind that we need to finish 8 modules by early June. Translated loosely, this means about a module every two weeks and it is now the end of February. Ask lots of questions folks...