First, students will learn what the law of sines is, and why it's true.

Proof of Law of Sines by dangarbo10

Next, students will learn how to use the law of sines to solve triangles. That is, students will learn how to determine all the unknown angles and side lengths of a triangle using the law of sines, given AAS or SSA. They'll learn how to solve both word problems and mathematical ones. Conclude by giving your students this challenge: In the figure below, find the area of the green triangle.

Here's the solution.

Conclude by giving your students these challenges:

- 1, 2, 3, 4, 5 by NRICH
- Geometric Parabola by NRICH
- Different by One by NRICH
- Twin Line-swapping Sudoku by NRICH
- 2016 AMC 8, Problem 12