Perhatikan segitiga ABC berikut


Aturan Sinus
$$\frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}$$
Aturan Cosinus
$$a^{2}=b^{2}+c^{2}-2bc\cos A$$
$$b^{2}=a^{2}+c^{2}-2ac\cos B$$
$$c^{2}=a^{2}+b^{2}-2ab\cos C$$
Luas Segitiga
$$L=\frac{1}{2}ab\sin C$$
$$L=\frac{1}{2}ac\sin B$$
$$L=\frac{1}{2}bc\sin A$$