Triangles
Trigonometry (the study of triangles) forms a huge component of the National 5 course spanning topics including Pythagoras, SOH CAH TOA, the Sine Rule, the Cosine Rule, Bearings, the CAST Diagram, Trigonometric Graphs and more. It plays an equally important role in all levels of maths you can pursue beyond the National 5 level. Below are some of the basic facts about triangles that you’ll need to know before tackling these more complex areas of trigonometry.
One of the most fundamental geometric facts about triangles is:
The interior angles of any triangle always sum to \boldsymbol{180^\circ}.
It is also important to understand the various types of triangles that can be constructed:
You will also be familiar with right-angled triangles. These can be either isosceles or irregular as these examples show: