As we’ve observed in class, in order to use the Law of Sines, you must know (or be able to find easily) an opposite angle-side pair in the triangle. But what if all you have is two sides and an angle? Is there anything we can do with that? Enter the Law of Cosines, a generalization of the Pythagorean Theorem to non-right triangles.

## Today’s links

- Homework: HW 7.9 – Introducing Law of Cosines
- Notes
- Lesson Video 1 (Law of Cosines with SAS triangle)
- Lesson Video 2 (Law of Cosines with SSS triangle)

## IXL Modules

- Y.17 – Law of Sines –
*assigned as homework 3/8 to a score of 80* **Y.18****– Law of Cosines****Y.19 – Solve a triangle**

Advertisements