002 | Cosine Rule & Area of Triangle | Math 0580 || Torus Academia

Welcome to Lesson 002 of our Trigonometry series at Torus Academy! In this video, Raja Nadeem Amin explains trigonometry for non-right-angled triangles, focusing on the Cosine Rule (Law of Cosines) and calculating the Area of a Triangle when height is not given. 📌 In this lesson, you will learn: • The conditions required to apply the Cosine Rule: 1. Two sides and one included angle given (to find the opposite side) 2. All three sides given (to find any unknown angle) • How to easily memorize and rearrange the Cosine Rule formula without rote learning • Avoiding common calculator entry mistakes • Finding the area of any non-right triangle using Area = ½ · a · b · sin(C) • Step-by-step worked past paper questions rounded to 3 significant figures and 1 decimal place