1. Second Grade, Common Core Learning Task
Lesson Plan
The Greedy Triangle
Second Grade, Common Core Learning Task
Standard:
Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces. Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.
Student Objective Statement:
I can identify the different attributes of polygons.
I can identify different kinds of polygons based on their attributes.
I can create various polygons using different media.
I can describe in words what polygons are.
Essential questions: Where do you see polygons? In what ways are polygons used?
Activities & Sequencing:
Hook/Engage (5 mins):
Think, Pair, & Share: What is a polygon?
Create an anchor chart:
Using stick notes write down what you think a polygon could be and add it to the class circle map. You can change your mind later.
Sequence of whole group, small group, & Independent work:
Set the purpose by asking questions introducing vocabulary slides 4-8 (5-10 mins).
2. Read the story (5-10 mins).
Review expectations, small group/partner assignments and mathematical practices. Students break into groups to create shapes using geo-boards (10-15mins).
Transition Time - report back to whole group. Think, Pair, & Share: What is a polygon? Make changes to the anchor chart. Add permanent writing. (3-6 mins).
Whole group or with partners complete the Polygon Picture Glossary
Watch Shape video (5-10 mins)
Explore Shapes using “Foldable Glossary” (10mins).
Close/End of the Day review – Using performance based assessments
This can be treated as an exit slip if used for formative assessment. (5-10 mins)

2. Anchor
Chart
Geometry
Polygons
What do you know about polygons?

3. The Greedy Triangle
Written by Marilyn Burns

4. Materials The book The Greedy Triangle Crayons Pencils Geoboard
Smartboard
Paper from teacher

5. Introduction
This story is about a Triangle who wants to be more than just a Triangle. It believes that more angles and corners will make life better. So the Triangle visits the character the Shapeshifter. The Shapeshifter changes the Triangle into many different shapes.
Do you think some shapes are better than others and why?
How will the Shapeshifter change the Triangle into different shapes?
What shapes do you think the Triangle will turn into?

6. Polygons have.. Sides- Sides are the outside lines of a shape.
Angle: the space where two lines meet to make a corner.
Corner (VERTEX)- a corner is where the sides of the lines meet.

7. Vocabulary Quadrilateral Pentagon Hexagon
The next set of vocabulary words I will introduce
are quadrilateral, pentagon, and hexagon.
Quadrilateral
A quadrilateral has four sides and four corners. A baseball diamond is the shape of a quadrilateral.
Pentagon
A pentagon has five sides and five corners. A
soccer ball is made up of tiny pentagon shapes.
Hexagon
A hexagon has six sides and six corners. A
Bee hive cell is the shape of a hexagon.

8. Vocabulary Heptagon Octagon Nonagon Decagon
A hexagon is a seven sided shape with seven corners. A flower can be in the shape of a hexagon.
Octagon
An octagon is an eight sided shape with eight
corners. A stop sign is the shape of an
octagon.
Nonagon
A nonagon is a nine sided shape with nine
corners. The top of a building can be in the
shape of a nonagon.
Decagon
A decagon is a ten sided shape with ten
corners. A mirror can be in the shape of a
decagon.

9. During Reading Name of the shape Picture of the shape Number of sides
Number of corners 3 3
Triangle
Quadrilateral 4 4
Pentagon 5 5 6
Hexagon 6
Let’s have some fun reviewing our shapes.
CLICK

10. After Reading Geoboard Fun! What is the lesson the triangle learned?
What is the lesson you learned?
Let’s have some fun watching a video about shapes and sizes.
CLICK

12. Let’s have some fun watching a video about shapes and sizes.
CLICK

14. Quick Check:

16. Formative/Summative Performance Assessment

17. Formative/Summative Performance Assessment

18. Evaluation Points 3 2 1 Total Before Reading
Student will participate in brainstorming, making predictions, drawing the shapes, and listen carefully to the new vocabulary.
Student will partially participate in brainstorming, making predictions, drawing the shapes, and listen to the new vocabulary.
Student will not brainstorm, make predictions, draw the shapes and listen to the new vocabulary.
During Reading
Listens carefully to the story and participates in writing the numbers on their white board.
Partially listens to the story and write some of the numbers on their whiteboard.
Will not listen and write any of the numbers on the whiteboard.
After Reading
Creates all five shapes on their geoboard.
Creates three shapes on their geoboard.
Creates two or less shapes on their geoboard.
Beyond Reading
Create a shape book with five pictures and label all of the pictures.
Create a shape book with three pictures and label the pictures.
Create a shape book with two or less shapes and label the pictures.

20. Beyond Reading
You are going to become a shape detective. Your new assignment is to go home and cut out five pictures of different shapes from magazines, newspapers, food boxes and construction paper. You will bring the pictures to school and create your very own shape book. Have fun being a shape detective!

21. Works Cited
Burns, M. (1994). The Greedy Triangle. New York: Scholastic
Linehan, Anne (1992). Stretch-It! San Diego: Teaching Resource Center.

22. Lesson retrieved and altered on April 9, 2013 from: https://docs