### UHG36: Classical spherical trigonometry

This video presents a summary of classical spherical trigonometry. First we define spherical distance between two points on a sphere, then the angle between two lines on a sphere (i.e. great circles). After a quick reminder of the circular functions cos,sin and tan, we present the main laws: the (spherical) sine law, two Cosine laws, Pythagoras' theorem, Thales theorem, Napier's Rules, the law of haversines and a few more, namely Napier's and Delambre's Analogies.We will not be using these laws in any substantial way: shortly in this course we will redevelop the framework of spherical trigonometry in a completely new, simplified algebra fashion. We will obtain analogs of the above laws, but analogs that are much more rigorous, powerful and accurate.

Length:
34:48