Non-Right-Angled Triangles (AQA A-Level Mathematics): Flashcards

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

2 angles + 1 side (AAS or ASA)

2 sides + non-included angle (SSA)

$c^2 = a^2 + b^2 - 2ab \cos C$

$\cos C = \frac{a^2 + b^2 - c^2}{2ab}$

2 sides + included angle (SAS)

3 sides (SSS)

$\frac{1}{2}ab\sin C$

Sides opposite angles $A$, $B$, $C$

Angle between sides $a$ and $b$