TRIGONOMETRIE 3eme - Calculer une longueur avec COSINUS

Summary

This video explains how to calculate the length of a side in a right triangle using trigonometric functions like sine, cosine, or tangent. The presenter guides viewers through an example triangle, where one side length and an angle are known, while another side length is to be determined. By utilizing the cosine formula, the video demonstrates the process step-by-step, using the given angle and hypotenuse to calculate the adjacent side. The solution is calculated using a calculator, with the final answer provided as approximately 9.83. The video ends with an invitation to ask questions in the comments.