First, students will learn why the greater side subtends the greater angle, in any triangle. For a proof, read this or watch this. Next, students will learn why the converse is true. That is, the greater angle subtends the greater side. For a proof, read this. Then students will practice ordering the sides and angles of a triangle, when only some are given (video).

Conclude by giving your students these challenges:

- 2019 Math Kangaroo Levels 11-12 Problem #28 by STEM4all
- Summing Consecutive Numbers by NRICH
- 2011 AMC 8, Problem 21
- Elevator Ride by Pierce School: Problem / Solution

Find the area of the green square:

Here's the solution.