Pythagoras’ Theorem & Trigonometry

Pythagoras' theorem
Trigonometric ratios

TOA CAH SOH is applicable for only right-angled triangles

Obtuse angles
Sine rule
$\dfrac{a}{\sin A}=\dfrac{b}{\sin B}$
Cosine rule
$c^2=a^2+b^2-2 ab \cos C$
Area of triangle
$\text{Area of triangle}=\frac{1}{2}ab \sin C$
A bearing is a 3-digit positive number with units of degree to show direction clockwise from the north direction.