Biangular coordinates



In mathematics, biangular coordinates are a coordinate system for the plane where $$C_1$$ and $$C_2$$ are two fixed points, and the position of a point P not on the line $$\overline{C_1C_2}$$ is determined by the angles $$\angle PC_1C_2$$ and $$\angle PC_2C_1.$$

The sine rule can be used to convert from biangular coordinates to two-center bipolar coordinates.

Applications
Biangular coordinates can be used in geometric modelling and CAD.