LEARN NC

K–12 teaching and learning · from the UNC School of Education

What can you build with triangles?

http://illuminations.nctm.org/LessonDetail.aspx?ID=L233

A lesson plan for Grades 2–3 Mathematics

Provider: National Council of Teachers of Mathematics

About this resource

Appropriate grades
2–3
Subjects
mathematics (geometry)
Provider
National Council of Teachers of Mathematics

Legal

Creative Commons License

This catalog record is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License. This license applies to the content of this page only and does not apply to the referenced website.

Students explore ways of building different basic shapes from triangles and investigate three dimensional shapes constructed from triangles. Illuminations provides an activity sheet and instructions for completing the lesson. Students use cut outs of two triangles to construct various shapes and participate in a class discussion of their procedure.

Students will:

  • Explore ways of building different basic shapes from triangles.
  • Investigate three dimensional shapes constructed from triangles.
  • Communicate their findings to their peers.

NCTM Standards and Expectations:

  • Investigate, describe, and reason about the results of subdividing, combining, and transforming shapes.
  • Classify two- and three-dimensional shapes according to their properties and develop definitions of classes of shapes such as triangles and pyramids.
  • Identify, compare, and analyze attributes of two- and three-dimensional shapes and develop vocabulary to describe the attributes.
  • Build and draw geometric objects.

North Carolina Curriculum Alignment

Mathematics (2004)

Grade 2

  • Goal 3: Geometry - The learner will perform simple transformations.
    • Objective 3.01: Combine simple figures to create a given shape.
    • Objective 3.02: Describe the change in attributes as two- and three-dimensional figures are cut and rearranged.

Grade 3

  • Goal 3: Geometry - The learner will recognize and use basic geometric properties of two- and three-dimensional figures.
    • Objective 3.01: Use appropriate vocabulary to compare, describe, and classify two- and three-dimensional figures.