Videos, examples, solutions, and lessons to help Grade 3 students learn how to find areas by decomposing into rectangles or completing composite figures to form rectangles.
Common Core Standards: 3.MD.6, 3.MD.7a, 3.MD.7b, 3.MD.7c, 3.MD.7d, 3.MD.5
New York State Common Core Math Module 4, Grade 3, Lesson 13 and Lesson 14
Lesson 13 Application Problem
Anil finds the area of a 5 inch by 17 inch rectangle by breaking it into 2 smaller rectangles. Show one way that he could have solved the problem. What is the area of the rectangle?
Note: This problem reinforces the strategy of breaking a larger shape apart into 2 smaller shapes to find the total area.
Lesson 13 Concept Development
Problem 1: Add using the break apart strategy to find area of a composite shape.
Problem 2: Subtract to find area of a composite shape.
Problem 3: Subtract to find area of a composite shape with missing side lengths.
Lesson 13 Problem Set
Lesson 13 Homework
Lesson 14 Application Problem
a. Break apart the shaded figure into 2 rectangles. Then add to find the area of the shaded figure below.
b. Subtract the area of the unshaded rectangle from the area of the large rectangle to check your answer in Part (a).
Note: This problem reviews G3–M4–Lesson 13’s concept of finding area of composite shapes. Students may choose to break apart their rectangles in different ways for Part (a).
Lesson 14 Concept Development
Problem 1: Choose an appropriate method for finding the area of a composite shape.
Problem 2: Solve a word problem involving area of non- rectangular shapes.
Lesson 14 Homework
Try the free Mathway calculator and
problem solver below to practice various math topics. Try the given examples, or type in your own
problem and check your answer with the step-by-step explanations.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.