In this Desmos activity, adapted for adult education by Carol Cashion, students explore the relationship between the area of triangles and rectangles using both a sketch tool and geometric formula.
Here are a few sample screens from the progression:
![](https://i0.wp.com/www.collectedny.org/wp-content/uploads/2022/05/image-12.png?resize=604%2C329&ssl=1)
![](https://i0.wp.com/www.collectedny.org/wp-content/uploads/2022/05/image-11.png?resize=604%2C343&ssl=1)
![](https://i0.wp.com/www.collectedny.org/wp-content/uploads/2022/05/image-13.png?resize=604%2C342&ssl=1)
![](https://i0.wp.com/www.collectedny.org/wp-content/uploads/2022/05/image-14.png?resize=604%2C291&ssl=1)