Curriculum Outcomes
Geometry: Develop spatial sense.
1. Solve problems by using the sine law and cosine law, excluding the ambiguous case.
[CN, PS, V]
Geometry: Develop spatial sense.
1. Solve problems by using the sine law and cosine law, excluding the ambiguous case.
[CN, PS, V]
Things You Need to Know
- You will be given a formula sheet for this unit. Focus more on how and when to use these formulas.
- Trigonometry is the branch of mathematics that deals with sides and angles in triangles.
- In previous years, you would have covered how to solve right triangles:
- Want to find a side in a right triangle:
- Use Pythagoras' Theorem if you have two sides already.
- Use sin, cos, or tan. Remember: SOHCAHTOA
- sin A = opposite / hypotenuse
- cos A = adjacent / hypotenuse
- tan A = opposite / adjacent
- Want to find an angle in a right triangle:
- Use the 180 degree rule (all angles must add up to 180 degrees)
- This rule works in all triangles, actually.
- Use inverse sin, cos, or tan.
- Set up the regular trig ratio, get a decimal to 4 places, then use inverse sin, cos, or tan.
- Use the 180 degree rule (all angles must add up to 180 degrees)
- Want to find a side in a right triangle:
- If you have an oblique triangle (not a right triangle), things are a bit different.
- Sine Law and Cosine Law:
- We generally want to use sine law. Only use cosine law if you have one of these two scenarios:
- 1. You only know 2 sides and the enclosed angle between them.
- 2. You only know all 3 sides, but no angles.
Interactive Activities
Sample Problems
Class Notes