Understanding Right Triangle Trigonometry

This page provides a comprehensive overview of solving right-angled triangles using trigonometric ratios. The content focuses on practical applications of trigonometry to find unknown sides of a right triangle.

Definition: SOH CAH TOA is a mnemonic device for remembering the three main trigonometric ratios: Sine (Opposite/Hypotenuse), Cosine (Adjacent/Hypotenuse), and Tangent (Opposite/Adjacent).

Example: In a right triangle ABC with angle of 32°, BC = 3.9 cm, the length of AB is calculated using tangent: AB = 3.9 × tan(32°)

Vocabulary:

• Côté Adjacent: The side adjacent to an angle
• Côté Opposé: The side opposite to an angle
• Hypoténuse: The longest side of a right triangle

Highlight: When solving trigonometric problems, it's crucial to first identify which triangle you're working with and clearly state which angle you're referencing.

Quote: "Le triangle ABC est rectangle en B alors je peux utiliser la trigonométrie" (Triangle ABC is right-angled at B, therefore I can use trigonometry)

The page demonstrates two specific calculations:

1. Finding AB using tangent: AB = 3.9 × tan(32°)
2. Finding AC using cosine: AC = 3.9 ÷ cos(32°) = 4.59 cm