In this video I go through two basic questions using the cosine rule. The first is a question where you are required to find an unknown side and in the second you are asked for an unknown angle.
Credit: Patrick Maye (Maths Teacher)

Congruency and similarity in triangles. More free lessons at: http://www.khanacademy.org/video?v=eF6zYNzlZKQ Note: All Khan Academy content is available for free at (www.khanacademy.org)

At last - Euclid and his friends explain how many different kinds of Triangle there are.With award winning illustrator, Shoo Rayner, who has illustrated well over 200 children's books for famous authors and for his own stories.