I think its worth while to give a very brief review of the trigonometric functions sine, cosine, etc. as well as a brief intro to calculating angles using spherical trig. Even if you know plane trig you should look at those web pages. I include a table of exact expressions for some standard angles.
If you are at all interested in calculating the angles involved in geodesic domes, you will be interested in the section on spherical trig. I give some explanation on how to use the "standard" spherical trig formulas. (These days there are computer programs for calculating all the data for geodesic domes so that it is not critical that you understand spherical trig. for building domes.) Also, these equations are the basis for calculating the great circle arc data for the VE and icosahedron LCD spherical triangles.
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