3.43 The Cosine Rule GCSE Higher PowerPoint Lesson

In this 22-slide lesson, students will explore the cosine rule to find missing side lengths and angles in non-right-angled triangles. They will learn how and when to apply the formula, recognising the key difference between using the sine rule and cosine rule depending on the information given. Through worked examples and problem-solving tasks, students will develop fluency in rearranging the formula and interpreting geometric contexts. The lesson builds on prior knowledge of triangle properties and trigonometric relationships, preparing students for exam-style, multi-step problems involving non-right-angled triangles.

Note this lesson is for the higher tier.

The lesson includes:

• Clear, guided examples

• Discussion opportunities from Think, Pair, Share

• Mini whiteboard section to check understanding and clarify misconceptions

• One structured task to practise key skills

• Challenge activity to extend and deepen learning

Perfect for engaging learners while reinforcing essential geometry concepts.