Lesson 9

Describing and Analyzing Shapes

Est. Class Sessions: 1–2

Summarizing the Lesson

After students have completed Check-In: Question 5 in the Student Activity Book, have the class complete a class shape chart for rhombuses.

Play Name That Property using the Power Polygons™. Make a two-column table. Label the columns “Yes” and “No.”

Tell students:

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  • Watch carefully as I sort shapes into two sets, one shape at a time. If a shape has my secret property, I will put it in the “Yes” column. If a shape does not have the property, I will put it in the “No” column.
  • Do not guess out loud. When you think you know the property, find a shape that also belongs in the “Yes” column. Raise your hand, and I will ask you to place it in the column silently. When several shapes have been added correctly, we will name the property.

Figure 10 shows a possible table for the property, “All angles are equal.” If there is not a single shape available that matches the rule, students can make a shape with two or more polygons. Have students challenge one another. Possible rules include:

  • Has a right angle
  • Has an obtuse angle
  • Is a quadrilateral
  • All sides are equal
  • All sides and all angles are equal
  • Has at least one pair of parallel sides
Student Guide:
Student Activity Book:
Master:
Shapes sorted for the rule, “All angles are equal”
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