Introduction
Right-angled triangles (that is triangles where one of the angles is ) are the easiest topic for introducing trigonometry. Since the sum of the three angles in a triangle is it follows that in a right-angled triangle there are no obtuse angles (i.e. angles greater than ). In this Section we study many of the properties associated with right-angled triangles.
Prerequisites
- have a basic knowledge of the geometry of triangles
Learning Outcomes
- define trigonometric functions both in right-angled triangles and more generally
- express angles in degrees
- calculate all the angles and sides in any right-angled triangle given certain information