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)

Introduction to trigonometry
More free lessons at: http://www.khanacademy.org/video?v=Jsiy4TxgIME
Note: All Khan Academy content is available for free at (www.khanacademy.org)

Worked example using the theorem of Pythagoras to solve a modelled word problem. More free lessons at: http://www.khanacademy.org/video?v=eF6zYNzlZKQ Note: All Khan Academy content is available for free at (www.khanacademy.org)

Introduction and overview of the Pythagorean theorem. More free lessons at: http://www.khanacademy.org/video?v=eF6zYNzlZKQ Note: All Khan Academy content is available for free at (www.khanacademy.org)