Law of Tangents
Let a Triangle have sides of lengths 
, 
, and 
and let the Angles opposite these sides by
, 
, and 
. The law of tangents states
An analogous result for oblique Spherical Triangles states that
See also Law of Cosines, Law of Sines
References
Abramowitz, M. and Stegun, C. A. (Eds.). Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, 9th printing. New York: Dover, p. 79, 1972. Beyer, W. H. CRC Standard Mathematical Tables, 28th ed. Boca Raton, FL: CRC Press, pp. 145 and 149, 1987.
- Irrational Number
- Irreducible Matrix
- Irreducible Polynomial
- Irreducible Representation
- Irreducible Semiperfect Number
- Irreducible Tensor
- Irredundant Ramsey Number
- Irreflexive
- Irregular Pair
- Irregular Prime
- Irregular Singularity
- Irrotational Field
- Isarithm
- ISBN
- I-Signature
- Island
- Isobaric Polynomial
- Isochronous Curve
- Isoclinal
- Isocline
- Isoclinic Groups
- Isodynamic Points
- Isoenergetic Nondegeneracy
- Isogonal Conjugate
- Isogonal Line