3.29 Introduction to Trigonometry GCSE PowerPoint Lesson

In this 46-slide lesson, pupils will learn how to identify the sides of a right-angled triangle in relation to a given angle, labelling the opposite, adjacent, and hypotenuse correctly. They will explore the definitions of sine, cosine, and tangent by forming fractions that compare the lengths of these sides, without yet calculating missing values. Using a range of right-angled triangle diagrams, pupils will write expressions for sin x, cos x, and tan x as ratios such as opposite over hypotenuse, and discuss how these ratios depend on the position of the angle. The lesson will focus on building a strong conceptual foundation and accurate use of trigonometric language in preparation for solving problems in future lessons.

The lesson includes:

• Clear, guided examples

• Discussion opportunities from Think, Pair, Share

• Mini whiteboard section to check understanding and clarify misconceptions

• Two structured tasks to practise key skills

• Challenge activity to extend and deepen learning

Perfect for engaging learners while reinforcing essential geometry concepts.