The basic idea on which the whole of trigonometry is based is that triangles (and other objects) can have the same shape but different sizes, and that if the angles of two triangles are equal, then the corresponding sides are in proportion. Such triangles are then said to be similar triangles. Trigonometry starts with right angled triangles, for which the side lengths are related by Pythagoras’ Theorem. This section reviews these ideas, which are fundamental to trigonometry as well as being important in their own right.
1. Read the Study Notes and Discussion for this module, and make sure that you have absorbed the main points by answering the questions.
2.
Follow the
instructions
regarding Further Practice until you have achieved
the Learning
Objectives for this section..