Trigonometry: Sine, Cosine, Tangent

🎬 Video Tutorial

(0:01) Basic Trigonometry: Sine, cosine, and tangent depend only on the angle $\theta$ in a right-angled triangle; they do not change with the size of the triangle.
(0:22) Trigonometric Ratios: $\sin \theta = \large \frac{\text{opposite}}{\text{hypotenuse}}$, $\cos \theta = \large \frac{\text{adjacent}}{\text{hypotenuse}}$, $\tan \theta = \large \frac{\text{opposite}}{\text{adjacent}}$.
(0:56) Solving for Sides: Use trigonometric ratios with a known angle and side to find missing sides of the triangle.
(2:14) Finding Angles: Find the unknown angle $\theta$ using inverse functions like $\cos^{-1}$ on a calculator.
(3:04) Key Angle Values: Memorise trigonometric values for common angles (30°, 45°, 60°) to simplify calculations.