Geometry, Teacher\'s Edition

(Axel Boer) #1

Trapezoids, Rhombi and Kites


I.SectionObjectives



  • Understand the relationships between the areas of two categories of quadrilaterals: basic quadrilaterals and
    special quadrilaterals.

  • Derive area formulas for trapezoids, rhombi and kites.

  • Apply the area formula for these special quadrilaterals.


II.Cross-curricular-RoomDesign



  • Tell students that they are going to design a room that has a trapezoidal shape.

  • Students can complete this in connection with the Technology Integration if you choose.

  • If not, have the students use the dimensions of their own bedroom (they did this in the last lesson), or the
    classroom or a standard size bedroom( 11 × 10 )for example.

  • Students are going to redesign this area as a trapezoid.

  • They want to come as close to the original area as possible.

  • So if the room was 11×10, the area is 110 sq feet.

  • How can you come close to the same area if the shape of the room is a trapezoid?

  • Students should draw their design on grid paper and explain their thinking.

  • Allow time for students to share their work when finished.


III.TechnologyIntegration



IV.NotesonAssessment



  • Assessment will come with student presentations and work product.

  • What did students learn about the relationship between rectangles and trapezoids?

  • Were they able to come up with a room with an area close to the original?

  • Who got the closest?

  • Provide students with feedback on their work.


Area of Similar Polygons


I.SectionObjectives



  • Understand the relationship between the scale factor of similar polygons and their areas.

  • Apply scale factors to solve problems about areas of similar polygons.

  • Use scale models or scale drawings.


II.Cross-curricular-NationalMallMapping


3.10. Perimeter and Area

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