Sine and Cosine Rules (HSC SSCE Mathematics Advanced): Quizzes

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

Two angles & one side OR two sides & non-included angle

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

Because $\sin(180° - \theta) = \sin \theta$

$b \sin A \leq a < b$

$143.1°$

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

Two sides & included angle OR three sides

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

It has no ambiguous case