SPHERICAL TRIGONOMETRY

For a right triangle, ABCon a sphere of radius r, with right angle at vertex Cand sides length a;b;cis defined: cos c r = cos a r cos b r This equation can equivalently be written as cos(c) = cos(a)cos(b) when the radius is 1. Proof. Consider a spherical triangle on the surface of a sphere with radius r, and sides a;b;c. Let vertex Cin the ... ................
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