Sine Rule, Cosine Rule and Triangle Area Rule Revision Videos

We've done the hard work for you, and put together the best revision videos on the sine, cosine and triangle area rules (the area of a non-right-angled triangle).

These videos show you how to use the sine and cosine rules to find missing angles and sides of non-right-angled triangles. Also covered, is how to use the formula for finding the area of a non-right-angled triangles, A = ½absin C

Sine Rule

This video shows how to find missing angles and sides using the sine rule.

Cosine Rule

The first of these two revision videos explains how to find the missing sides in any triangle using the cosine rule. The second video shows you how to use the same rule to find the angles when they are missing. The latter requires a good understanding of rearranging formulae.

Triangle Area Rule

This shows you how to use the formula A = ½absin C

Although this topic is generally thought of as being for higher ability students, it's actually very easy to use this formula. Everyone taking higher tier GCSE should have looked at this video so you can access marks if a question on this comes up in the exam.