Math Trigonometry Set B 02 Non Right Angled Triangles Cosine Rule Calculating an Angle Mostly for Year/Grade 10 and 11

Some students prefer to use the triangle using capital letters on the corners (vertices), some don't. This video deals with both cases.

Be careful that your calculator is set on degrees, otherwise your answer will be incorrect.

After 40 years of enjoyable and rewarding teaching, I still love and continue to teach. It still amazes me how I continue to still think of better ways of teaching mathematical concepts and I also continue to discover methods of explaining things that help students 'better' understand and become more successful at remembering the concepts.

A word of warning from what I have repeatedly seen over the years - most of my videos are placed in a logical or reasonably sequential order and if you watch the first or second video in a playlist and feel comfortable with the concepts, please go to the last video in the playlist to check if you really are okay. Each video in a playlist usually becomes progressively more complex and the 'latter' or 'last' video will often contain common assessment questions where students are known to make errors.

I also often include some revision / consolidation / mixture videos in the playlist which I know are crucial to assist with student success in assessments.

I hope that you find this very helpful and a blessing in your studies.