1. Investigating Similar Triangles

2. TEKS §111.41. Geometry (c) Knowledge and skills.
(7) Similarity, proof, and trigonometry. The student uses the process skills in applying similarity to solve problems. The student is expected to:
(A) apply the definition of similarity in terms of a dilation to identify similar figures and their proportional sides and the congruent corresponding angles

3. Objective
In my Geometry lesson, Investigating Similar Triangles, for tenth graders I will discuss similar triangles. The objective of the lesson is to help students discover the properties of similar triangles and identify corresponding parts.

4. Content
Every student will receive four sheets of construction paper, a straight edge, compass, and marker. I will instruct the students to draw two similar triangles on each sheet of construction paper using Triangle Similarity Postulates (SSS, ASA, SAS, AAS).
Using their prior knowledge on congruent triangles and by discussing with their peers they should be able to draw similar triangles with the corresponding sides and angles matching up.
After students have finished we will work through proofs explaining exactly why the Postulates work for similar triangles.
After the lesson the students will take pictures of their similar triangles and proofs for each postulate. They will then use Mixbook to combine all their pictures into a digital picture book.

5. Mixbook
Mixbook is a technology tool that is used online to create custom photo books, cards, calendars, and wall canvases. This web-based tool would be used as a digital photo book containing the definition and postulates of similar triangles.
The students will be able to take pictures of their individual work and compose a colorful resource for notes.

6. Benefit of Mixbook
Students will be able to access their creation on any computer because Mixbook is web-based and students can use their login information to review their work at any time.
To expand the use of Mixbook I would also have students create their portfolio of their tenth grade Geometry year, so that they can see how everything they learned came together at the end of the course.

7. View Mixbook Creation