Description: Lesson 9 lays the foundation for the work to come in Lessons 10 and 11. In Lesson 10, students apply knowledge of the distributive property from Modules 1 and 3 to find area. In Lesson 11, students use a given number of square units to determine all possible whole number side lengths of rectangles with that area. Objective 1: Analyze different rectangles and reason about their area. Objective 2: Apply the distributive property as a strategy to find the total area of a larger rectangle by adding two products. Objective 3: Demonstrate the possible whole number side lengths of rectangles with areas of 24, 36, 48, or 72 square units using the associative property.