Content Area: Mathematics-Geometry
Unit Title: Similar Polygons (Rep-Tile Quadrilaterals–Connected Math Stretching & Shrinking)
Target Course/Grade Level: 7th grade Self Contained (BD/Cognitively Impaired)
Name: Charlotte Richardson
School: Lakeside Middle
Date: July, 2010
Students deepen their understanding of what it means for two figures to be similar. Through experiments with rep-tiles (shapes where copies are put together to make larger, similar figures), students explore the relationship between the scale factor of two similar figures. They also discover how triangles are special. These experiences help them build mental images to support their evolving ideas about the relationship between scale factor and area.
In previous grades, students have investigated area, perimeter, and congruency.
21st century themes
Global Awareness / Health Literacy
Students may use these skills in a career path of future academic endeavors. Students may need these skills in careers such as construction, masonry, engineering, etc. Furthermore, students will need these skills in order to continue through middle, high school, and possibly college.
Standards Key Ideas and Details
Draw, construct, and describe geometrical figures and describe the relationships between them.
7.G.1 Solve problems involving scale drawings of geometric figures, including computing actual lengths and areas from a scale drawing and reproducing a scale drawing at a different scale.
Unit Essential Questions
Unit Enduring Understandings
Unit Learning Targets
Evidence of Learning
Summative Assessment (1-2 days)
Students will complete a written test in order to demonstrate understanding of similar figures and scale factors. Test may be distributed in multiple forms in order to meet needs of individual students.
Pencil, Tests (multiple forms if necessary)
Stretching and Shrinking: Investigation 3 – 3.1 Rep-Tile Quadrilaterals
Teachers’ Guide pgs. 54-60
Student Workbooks pgs. 38-39
80 minutes/ 4-5 days
Stretching and Shrinking: Investigation 3 – 3.2 Rep-Tile Triangles
Teachers’ Guide pgs. 61-64
Student Workbooks pgs. 40-41
80 minutes/ 4-5 days
Stretching and Shrinking: Investigation 3 – 3.3 Scale Factors and Similar Shapes
Teachers’ Guide pgs. 65-68
Student Workbooks pgs. 42-43
80 minutes/ 4-5 days
Possible Brain Breaks:
***May use extension activity boxes to allow children who are not understanding completely, or finish early.
Curriculum Development Resources
Click the links below to access additional resources used to design this unit:
***Use with smart board to check understanding after finishing the connected math. Could be used as an extension if students do not grasp ideas.
***Use with SMARTBoard to have students manipulate various shapes and relate to scale factor. (Online manipulatives)
***YouTube video for YourTeacher.com about Similar Polygons.
***Use with students on the SMARTBoard or in the computer lab.
Lesson Plan 1
Content Area: Mathematics
Lesson Title: Similar Polygons
Timeframe: X hours/days
21st Century Themes
X Global Awareness-(Connect to Job Practicality)
Financial, Economic, Business, and Entrepreneurial Literacy
21st Century Skills
x Creativity and Innovation-(Creating File Folder Posters)
x Media Literacy-(Using internet/video clips to support learning)
x Critical Thinking and Problem Solving-(Exploring similar shapes and coming to individual conclusions)
x Communication and Collaboration
Life and Career Skills
Integration of Technology: SMARTBoard, Document Camera, Student Computers/Computer Lab
Equipment & materials needed:
SMART Board / Projector
Laptop / Internet Access
It’s All Similar to Me worksheet
Connected Math Teacher’s Manual / Student Workbooks
Interactive Student Notebooks (ISN)
Learning Activities/Instructional Strategies
** demonstrate how to take notes using the table handout and document camera.
***“Hold up a quadrilateral.”; “Find a tile that is not a quadrilateral.” , “Hold up a tile that has 4 sides…what is the mathematical term for a 4 sided figure?”
***record their findings on a table provided (same as for notes)
***glue into their interactive notebooks
***Discuss activity / share findings
*** draw similar figures on the SMART Board (4 or 5 pairs of figures).
-mark corresponding sides.
-discuss how they can find out if two figures are actually similar
***May use computer lab/student computers in class
***Discuss findings and realizations.
***Challenges / Extra Credit: Do the last 2 parts on the worksheet (Not required at this point).
Formative Assessment Tasks
Universal Design for Learning Options
Multiple Means of Representation
Multiple Means of Action and Expression
Multiple Means of Engagement