1. Lesson 4

1.8. Lesson 4 Summary

Mathematics 20-1 Module 2

Module 2: Trigonometry

 

Lesson 4 Summary
 

In Lesson 4 you investigated the following questions:

  • How can angles and sides in any triangle—oblique and right—be found?

  • How does your knowledge of solutions to equations of the form sin θ = k (from Lessons 1 and 2) affect solutions using the sine law?

You learned and applied a new formula, the sine law, that is valid for all triangles—both right and oblique.

 

 



textbook

You also learned that when using the sine law to solve for angles, you must be aware of something called the ambiguous case—depending on the angle and side measurements given in your problem, it may be possible to construct zero, one, or two triangles. Refer to “Key Ideas” on page 107 of the textbook for a summary of the conditions that result in zero, one, or two triangles.

 

In the next lesson you will learn about the cosine law.