LEARN NC

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

Describing reflections

http://illuminations.nctm.org/LessonDetail.aspx?ID=L470

A lesson plan for Grades 9–12 Geometry

Provider: National Council of Teachers of Mathematics

About this resource

Appropriate grades
9–12
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.

This investigation will help you to understand how reflections work and what happens when two or more reflections are applied one after the other. Illuminations provides interactive Java applets and detailed instructions for completing the lesson.

Students will:

  • Understand how reflections work and what happens when two or more reflections are applied one after the other.

NCTM Standards and Expectations:

  • Use various representations to help understand the effects of simple transformations and their compositions.
  • Understand and represent translations, reflections, rotations, and dilations of objects in the plane by using sketches, coordinates, vectors, function notation, and matrices.
  • Use geometric ideas to solve problems in, and gain insights into, other disciplines and other areas of interest such as art and architecture.

North Carolina Curriculum Alignment

Mathematics (2004)

Grades 9–12 — Geometry

  • Goal 2: Geometry and Measurement - The learner will use geometric and algebraic properties of figures to solve problems and write proofs.
    • Objective 2.01: Use logic and deductive reasoning to draw conclusions and solve problems.
    • Objective 2.04: Develop and apply properties of solids to solve problems.
  • Goal 3: Algebra - The learner will transform geometric figures in the coordinate plane algebraically.
    • Objective 3.01: Describe the transformation (translation, reflection, rotation, dilation) of polygons in the coordinate plane in simple algebraic terms.
    • Objective 3.02: Use matrix operations (addition, subtraction, multiplication, scalar multiplication) to describe the transformation of polygons in the coordinate plane