Reflection: Shared Expectations Definition of Similarity and Similar Triangles - Section 2: Practice: Similar Polygons


Since my students have solved problems using proportional reasoning prior to entering this class, I didn’t want to re-teach skills I knew they would be able to bring back on their own.  Instead, I wanted to focus students’ attention on why and how they could solve similar polygons.

As students worked through this set of practice problems, I asked them to consider a pair of questions that would encourage metacognition, which I posted on the board using the document camera.  I posed two questions to them: why can I do this? (when they used a particular solving strategy) and how do I know I can compare these sides? (when they looked for pairs of corresponding sides). 

By giving students a frame for working through these problems, I hoped to encourage them to solve in multiple ways that would make sense to them so long as they could justify which sides were corresponding and why their problem solving method made sense.  As I circulated the room while students corrected their work, I could see them connecting their work to the approaches shown in the answer key, which allowed me to see how they made sense of solving polygons in multiple ways.

  A Frame for Working Through the Task
  Shared Expectations: A Frame for Working Through the Task
Loading resource...

Definition of Similarity and Similar Triangles

Unit 12: Triangle Similarity and Trigonometric Ratios
Lesson 1 of 11

Objective: SWBAT apply the definition of similarity to identify measurements in similar figures. SWBAT to argue that HL is a “similarity shortcut” for right triangles.

Big Idea: Students' prior knowledge of transformations and congruence helps them make connections as they learn to use similarity shortcuts.

  Print Lesson
1 teacher likes this lesson
similar figures picture li
Similar Lessons
Radian measure Day 2 of 2
12th Grade Math » Trigonometry as a Real-Valued Functions
Big Idea: Through sharing of problem solving strategies students will develop a description for measuring angles in radians and use the relationship with degrees to find special angles.
Independence, MO
Environment: Suburban
Katharine Sparks
Satellite Overflight 1
Geometry » Scaling Up- Dilations, Similarity and Proportional Relationships
Big Idea: Students learn how dilating a shape affects perimeter and area as they design a sign large enough to show up on Google Earth.
Ault, CO
Environment: Rural
Tom Chandler
Dilation Nation
Geometry » Transformers and Transformations
Big Idea: Students will review transformations using a brain pop and learn how to geometrically enlarge and shrink shapes.
Saratoga Springs, NY
Environment: Suburban
Stephanie Conklin
Something went wrong. See details for more info
Nothing to upload