Trigonometry - SOHCAHTOA finding angles

A complete lesson on finding an angle in a right-angled triangle using trig ratios. Designed to come after pupils have been introduced to the ratios sin, cos and tan, and have investigated how the ratios vary. Please see my other resources for complete lessons on these topics.

Activities included:

Starter:
Provided with the graph of y=sinx, pupils estimate sinx for different values of x and vice-versa.

Main:

• Slides to introduce use of scientific calculators to find accurate values for angles or ratios.
• Examples of the basic method of finding an angle given two sides. Includes graphs to reinforce what is happening.
• Quick questions for pupils to try and provided feedback.
• A worksheet of questions with a progression in difficulty. Starts with standard questions, then moves on to more challenging ones (eg finding the smallest angle in a non-right-angled, isosceles triangle).

Plenary:
A final question to check pupils’ understanding, but also with a combinations/logic element.

Printable worksheets and answers included.

Please review if you buy as any feedback is appreciated!