Similar Triangles

   Contents

 Task

In this section, students use an object perpendicular to the ground, a meter stick or yardstick and their shadows to determine the height of the object. 


 GPS Addressed (click [+] to expand)

    [-] M7G3. Students will use the properties of similarity and apply these concepts to geometric figures.
      a. Understand the meaning of similarity, visually compare geometric figures for similarity, and describe similarities by listing corresponding parts.
    b. Understand the relationships among scale factors, length ratios, and area ratios between similar figures. Use scale factors, length ratios, and area ratios to determine side lengths and areas of similar geometric figures.
    [-] M7P3. Students will communicate mathematically.
     

    a. Organize and consolidate their mathematical thinking through communication.
    b. Communicate their mathematical thinking coherently and clearly to peers, teachers, and others.
    c. Analyze and evaluate the mathematical thinking and strategies of others.
    d. Use the language of mathematics to express mathematical ideas precisely.

    [-] M7P4. Students will make connections among mathematical ideas and to other disciplines.
     

    a. Recognize and use connections among mathematical ideas.
    b. Understand how mathematical ideas interconnect and build on one another to produce a coherent whole.
    c. Recognize and apply mathematics in contexts outside of mathematics.


 Video (duration: 19:55)

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Use these questions to guide your thinking about some of the important teacher ideas in the lesson featured in the video clip.

  1. How is the teacher helping the students tie mathematics to everyday life?
  2. How are drawings used in this lesson?
  3. What kinds of things are happening in this case to help the students and teacher understand each others' thinking?
  4. Consider the GPS standards listed with this video. How does the lesson featured in this video address each of these?
  5. What makes this lesson different from lessons you have taught on this topic? What is similar between this lesson and lessons you have taught?

 Classroom Materials / Lesson Outlines