Students will learn a formula to find the area of a triangle from SAS, and how the formula is derived. Here's a video covering the derivation. Then students will practice using the formula. Before attempting this section, students should know how to find the area of a triangle given its base and height. They should also know that sine is opposite over hypotenuse.

Conclude by giving your students these challenges:

- Lawn Border by NRICH
- Cutting a Cube by NRICH
- Advent Sudoku by NRICH

Find the distance \(\overline{AB}\,{:}\)

Here's the solution.