# Grade 3: Chapter 12 Two-Dimensional Shapes

**Grade 3: Chapter 12 –** Two-Dimensional Shapes

**Chapter Essential Question:** What are some ways to describe and classify two-dimensional shapes?

(Grade 2) /

**Chapter Twelve Standards**

Grade 3 / After

(Grade 4)

Reason with shapes and their attributes. (2.G.1, 2.G.2, 2.G.3) / Geometry 1: Understand that shapes in different categories (e.g., rhombuses, rectangles, and others) may share attributes (e.g., having four sides), and that the shared attributes can define a larger category (e.g., quadrilaterals). Recognize rhombuses, rectangles, and squares as examples of quadrilaterals, and draw examples of quadrilaterals that do not belong to any of these subcategories.

- I can identify and describe attributes of plane shapes.
- I can describe angles in plane shapes.
- I can identify polygons by the number of sides they have.
- I can determine if lines or line segments are intersecting, perpendicular, or parallel.
- I can describe, classify, and compare quadrilaterals based on their sides and angles.
- I can draw quadrilaterals.
- I can describe and compare triangles based on the number or sides that have equal length and by their angles.
- I can solve problems by using the strategy draw a diagram to classify plane shapes.

Geometry 2: Partition shapes into parts with equal areas. Express the area of each part as a unit fraction of the whole.

- I can partition shapes into parts with equal areas and express the area as a unit fraction of the whole.

Each day the math block will begin with 15 minutes of **Daily Math Review and Mental Math**. The focus of DMR should be either prerequisite standard skills or previous chapter concepts that were not mastered. The focus of mental math should be based on the current Chapter’s skills and concepts. Adjust the amount of questions in DMR and MM to fit into the 15 minute time block.

**Suggested Chapter Pacing**

*All lessons are paced for one day, unless otherwise indicated. Teachers may adjust to meet students’ needs. *

**Launching the Chapter**/ Pre-Assessment /

**Review Prerequisite Skills**

Compare It! TE 695I /

**Show What You Know Assessment**

Identify Tier 2 and Tier 3 Groups for Small Group Instruction.

**Day Before Lesson 12.1**/

**Vocabulary Activity**

Develop vocabulary for geometry. 695H /

**Vocabulary Builder**

Identify students who will need further vocabulary support for Chapter 12. /

**Preview Chapter Centers**

Introduce chapter games, activities, and literature students will be using during center time. /

**School – Home Letter**

Read together and send home.

I Can Statement /

**Essential Question**/

**Implementation Notes**

Lesson 12.1

Geometry 1 / I can identify and describe attributes of plane shapes. / What are some ways to describe two-dimensional shapes? /

- Introduce Activities:
*Classification Act and Figure It Out*

Lesson 12.2

Geometry 1 / I can describe angles in plane shapes. / How can you describe angles in plane shapes? /

- Bendable straws, scissors OR pipe cleaners OR two pieces of sentence strips with a brad
- Introduce Activity: What Figure?

Lesson 12.3

Geometry 1 / I can identify polygons by the number of sides they have. / How can you use line segments and angles to make polygons?

Lesson 12.4

Geometry 1 / I can determine if lines or line segments are intersecting, perpendicular, or parallel. / How can you describe line segments that are sides of polygons? /

- Mid Chapter Checkpoint not required

Lesson 12.5

Geometry 1 / I can describe, classify, and compare quadrilaterals based on their sides and angles. / How can you use sides and angles to help you describe quadrilaterals?

Lesson 12.6

Geometry 1 / I can draw quadrilaterals. / How can you draw quadrilaterals? /

- Ruler

Lesson 12.7

Geometry 1 / I can describe and compare triangles based on the number of sides that have equal length and by their angles. / How can you use sides and angles to help you describe triangles?

Lesson 12.8

Geometry 1 / I can solve problems by using the strategy draw a diagram to classify plane shapes. / How can you use the strategy draw a diagram to classify plane shapes? /

**Possible 2 day lesson**

Lesson 12.9

Geometry 2 / I can partition shapes into parts with equal areas and express the area as a unit fraction of the whole. / How can you divide shapes into parts with equal areas and write the area as a unit fraction of the whole? /

**Possible 2 day lesson**- Pattern blocks, colored pencils, ruler
- Review Literature: The Whole Picture

Resources and Centers for Chapter 12

Technology / Hands-On Resources / Centers

Digital Lesson: Engage / Bendable Straws / Activity: Classification Act

Fastt Math / Colored Pencils / Activity: Figure It Out

Interactive White Board Lesson / Counting Tape / Activity: What Figure?

Interactive Student Edition / Math Board / Literature: The Whole Picture

Math on the Spot Videos / Math Journal

iTools: Geometry / Pattern Blocks

iTools: Measurement / Rulers

Mega Math / Scissors

Personal Math Trainer /

*Other Hands-On Resources may be needed for Small Group Instruction*

Additional Resources for Chapter 12

Geometry 1 / Geometry 2

What is a Rectangle (Video) / Fraction Review

Sorting Quadrilaterals

Rectangles and Parallelograms

What is a Polygon (Video)

2 and 3 Dimensional Figures (2D only)

Analyzing Quadrilaterals

Des Moines Public Schools 2014-2015 Math Curriculum Guides Page | 1

Grade 3 – Chapter 12