LEARN NC

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

How many triangles can you construct?

http://illuminations.nctm.org/LessonDetail.aspx?ID=L236

A lesson plan for Grades 3–5 Mathematics

Provider: National Council of Teachers of Mathematics

About this resource

Appropriate grades
3–5
Subjects
mathematics (geometry)
Provider
National Council of Teachers of Mathematics

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Students identify patterns in a geometrical figure (based on triangles) and build a foundation for the understanding of fractals. Illuminations provides activity sheets and detailed instructions for completing the lesson.

Students will:

  • Identify patterns in a geometrical figure.
  • Build a foundation for the understanding of fractals.
  • Make hypothesis and then develop experiments to test them.

NCTM Standards and Expectations:

  • Investigate, describe, and reason about the results of subdividing, combining, and transforming shapes.
  • Make and test conjectures about geometric properties and relationships and develop logical arguments to justify conclusions.
  • Build and draw geometric objects.

North Carolina Curriculum Alignment

Mathematics (2004)

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.

Grade 4

  • Goal 3: Geometry - The learner will recognize and use geometric properties and relationships.
    • Objective 3.01: Use the coordinate system to describe the location and relative position of points and draw figures in the first quadrant.
    • Objective 3.03: Identify, predict, and describe the results of transformations of plane figures.
      • Reflections.
      • Translations.
      • Rotations.

Grade 5

  • Goal 3: Geometry - The learner will understand and use properties and relationships of plane figures.
    • Objective 3.01: Identify, define, describe, and accurately represent triangles, quadrilaterals, and other polygons.
    • Objective 3.02: Make and test conjectures about polygons involving:
      • Sum of the measures of interior angles.
      • Lengths of sides and diagonals.
      • Parallelism and perpendicularity of sides and diagonals.