Non-Right-Angled Triangles (Edexcel A-Level Mathematics): Quizzes

Two angles and one side (AAS or ASA)

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

The side opposite angle $A$

Two sides and included angle or three sides

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

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

$8.57$ cm

$111.5°$

$\text{Area} = \frac{1}{2}ab\sin C$

$12$ square cm