- Students should be commenting that because the angle measures are all the same, that the side lengths will be
proportional. - Then have students pair up.
- These two students need to compare their kite designs.
- They need to write four different proportions comparing the side lengths of the kites.
- Then have students design a statement of similarity that best compares their kites.
- If they can figure out the scale factor between the two kites have them include that in their work.
- Allow time for the student to share their work when finished.
III.MeetingObjectives
- Students will recognize similar polygons in their kite designs.
- Students will identify and explain similar side lengths of the kite design.
- Students will write proportions to show similarity.
- Students will calculate scale factors.
IV.NotesonAssessment
- Assess student work by walking around and observing students as they work.
- Then assess student understanding during student presentations.
- Help students to make connections about similar polygons by asking questions and providing feedback.
Similarity by AA
I.SectionObjectives
- Determine whether triangles are similar.
- Understand AAA and AA rules for similar triangles.
- Solve problems about similar triangles.
II.ProblemSolvingActivity-ThalesandthePyramids
- This is a great lesson to use Thales and the simple way that Thales measured the pyramids.
- You can use this website to find out more information about Thales.
- http://educ.queensu.ca/ fmc/april2002/Pyramids.htm
- Essentially, Thales figured out the height of the pyramids by using his own height. He waited until his shadow
equaled his height. Then he measured the height of the pyramid and he knew that the height of the pyramid
was equal to the pyramid’s height. - Here is the problem.
- “Stan is 6 feet tall. When he goes outside, his shadow is only nine feet long. The shadow of the tree in his
yard is eighteen feet long. Based on these numbers, what is the height of the tree?” - Use a drawing to figure out the answer to this problem.
- Have students write a paragraph to explain their process and how they arrived at their answer.
- When finished, have the students share their work in small groups.
III.MeetingObjectives
- Students will determine similar triangles.
- Students will understand AAA and AA for similar triangles.
Chapter 5. Geometry TE - Problem Solving