Building on young mathematicians' prior knowledge of three-sided shapes, this instructional activity series explores the defining characteristics of different types of triangles. Starting with a shared reading of the children's book The Greedy Triangle, children go on to create triangles using geoboards and flexible straws, complete a series of worksheets, and, finally, demonstrate their learning on a short quiz.

Additional Tags

math

Show More Show Less

Instructional Ideas

• Use this lesson series to introduce an upper elementary geometry unit on triangles
• At the end of the series, break students into six groups and have each create a poster describing a different type of triangle; use their work to create a classroom bulletin board

Classroom Considerations

• A copy of the book The Greedy Triangle by Marilyn Burns is used to introduce the first lesson. If you do not own a copy, one can most likely be found in your school or local library
• Depending on the availability of materials in your classroom, you may want to consider letting students work on some of the activities with a partner or small group

Pros

• Offers a wide selection of worksheets and activities that support students with learning how to classify triangles
• A list of necessary materials are included for each of the three lessons
• Each lesson includes a clear set of procedures, an imbedded assessment, and ideas for reteaching or extending learning about triangles

Cons

• None

Common Core

4.G.A.2 5.G.B.3 5.G.B.4 MP6 MP7