# Lesson 1

Areas Around Areas

These materials, when encountered before Algebra 1, Unit 7, Lesson 1 support success in that lesson.

### Lesson Narrative

In this lesson, students practice finding the area of the region between rectangles when one is contained by the other. In the associated Algebra 1 lesson, students create frames around rectangular regions and explore the area of the frame. By first exploring the area of the region between 2 rectangles, students will be prepared to use quadratic equations to represent the area of the frames they create. Students look for and express regularity in repeated reasoning (MP8) when they find the area of rectangles and create expressions with variables to represent the area between 2 rectangles. They also reason abstractly and quantitatively (MP2) when they interpret the situations into drawings and expressions.

### Learning Goals

Teacher Facing

• Practice finding unknown area and side lengths of the region between 2 rectangles.

### Student Facing

• Let’s explore rectangle areas