Sinussatz

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

$\displaystyle \ a : b : c = \sin \alpha : \sin \beta : \sin \gamma$ (Verhältnisgleichung) $\displaystyle$

Wenn $\displaystyle \alpha = 90^\circ : \quad \sin \beta =\frac{b}{a} \qquad \sin \gamma =\frac{c}{a}$