Build A Shape with the Book “The Greedy Triangle”

Dec 4, 2014

I don’t know about you, but I love integrating literature with math.  This is such a fun lesson to work on Geometry and get your students moving!

It is a three-part whole group lesson intended for first grade, but it could be adapted for K-2.
The lesson can be completed in a day, or broken up if needed.

MCC1.G.1 Distinguish between defining attributes versus non-defining attributes; build and draw shapes to possess defining attributes.

MCC1.G.2 Compose two-dimensional shapes or three-dimensional shapes to create a composite shape, and compose new shapes from the composite shape.

Read The Greedy Triangle, a book about a shape that wanted to be something else. Discuss the shapes in the story, what the shape-shifter does to create a new shape (adds one side and one angle) and the real-world connections in the pictures. As you are reading, record any new information from the story on chart paper.

Ask students if they think they could build shapes using their bodies. Give each child a long piece of yarn (or other similar material) to use to create a shape. Call out a shape and have students create a way to use their bodies and the yarn to make the shape. (For example, name a triangle for students to make. Students could spread their feet apart while standing on the yarn, lift up the two ends of the yarn and bring the two ends together with raised hands to create a triangle.) Repeat this activity by naming several other shapes for students to create independently or with a partner.

Teachers at the Wayne RESA TIPM course having fun making shapes with each other.

Students will use straws, pipe cleaners, or other manipulatives to recreate a triangle, rectangle, square and trapezoid. Tell the students that the straws are the sides and the pipe cleaners are the corners. Model how to connect the straws and pipe cleaners to create a shape. The teacher will read The Greedy Triangle aloud to the students again. The students will create the shapes with the straws and pipe cleaners as the teacher comes to each shape. This will allow students to practice constructing shapes with the materials provided.

Teachers at the Wayne RESA TIPM course working hard to build shapes with pipe cleaners and straws.


  1. Challenge students to make other shapes with the straws and pipe cleaners. Ask students questions similar to: “Would you still have a triangle if two sides were longer than the third side? Why or why not?”
  2. Allow students to explore creating a cube with the straws and pipe cleaners.

Click HERE for the complete “Build A Shape”  lesson from Georgia Department of Education.
Click HERE for the recording sheet.


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