Lesson objective: Find missing lengths of sides when the area is known.

This lesson helps to build procedural skill with finding missing dimensions when given the area. Solving equations is used here because it supports students’ developing algebraic skills. This work develops students' understanding that unknown measurements can be found when the area of the figure and sufficient information are given.

Students engage in Mathematical Practice 2 (Reason abstractly and quantitatively) as they substitute known values into formulas and solve for the missing value in the resulting equation.

**Key vocabulary:**

- area
- base
- height