Mollweide's formula [SEP] named after
Mollweide's formula
In trigonometry, Mollweide's formula, sometimes referred to in older texts as Mollweide's equations, named after Karl Mollweide, is a set of two relationships between sides and angles in a triangle.
It can be used to check solutions of triangles.
Let "a", "b", and "c" be the lengths of the three sides of a triangle.
Let "α", "β", and "γ" be the measures of the angles opposite those three
- Mollweide's first formula. From the addition formula and the law of cotangents we have
- Mollweide's second formula. From the addition formula and the law of cotangents we have
- The law of tangents can also be derived from this .
See also.
- Law of sines
- Law of cosines
- Law of tangents
- Mollweide's formula