In addition to the Law of Sines, the Law of Cosines, and the Law of Tangents, there are numerous other identities that apply to the three angles A, B, and C of any triangle (where A+B+C=180° and each of A, B, and C is greater than zero). Some of the most notable ones follow:
These are all direct consequences of Pythagoras's theorem.
Sum/Difference of anglesEdit
Product to SumEdit
Sum and difference to productEdit
- , where and
These are all direct consequences of the sum/difference formulae
In cases with , the sign of the result must be determined from the value of . These derive from the formulae.