Erweiterter Sinussatz:

$$\frac{a}{\sin \alpha }=\frac{b}{\sin \beta }=\frac{c}{\sin \gamma }=2r$$

$$a = 2 r\,\sin \alpha \qquad b = 2 r\,\sin \beta \qquad c = 2 r\,\sin \gamma$$

$$r =\frac{abc}{4F}$$