Maths — Sine & Cosine Rules

\frac{a}{\sin A} = \frac{b}{\sin B} = \frac{c}{\sin C}

a^2 = b^2 + c^2 - 2bc\cos A

\text{Area} = \tfrac{1}{2}ab\sin C

\cos A = \frac{b^2 + c^2 - a^2}{2bc}