Unit 1, Lesson 13

# Find the area of a rectilinear figure by breaking it into two smaller rectangles

North Carolina Department of Public Instruction 63 min(s)

In this lesson, students transition from finding the areas of rectangles to finding the areas of rectilinear figures (combined rectangles). This lesson expects students to break the figure into rectangles, and use the dimensions of smaller rectangles to determine the area. Some students may visualize the rectilinear figure as one large rectangle with a "piece missing," consequently finding the dimensions of this larger rectangle, then subtracting the "missing" portion to find the area of the figure. By the end of the lesson students will be able to find the area of a large, rectilinear figure by decomposing it into smaller rectangles, communicate their process of finding the area of a rectilinear figure, find areas of rectilinear figures by decomposing them into non-overlapping rectangles and adding the areas of the nonoverlapping parts, applying this technique to solve real world problems.