Lesson Plan
Curated OER

The Attack of the Manhole Monsters

For Teachers 9th - 12th
High schoolers explore the concept of similarity. They examine such topics as ratio of corresponding sides, internal ratios and scaling factors. After watching a video, student groups perform experiments outside the school building.
Worksheet
Curated OER

A Geometry Worksheet - Similar Triangles

For Students 9th - 12th Standards
In this similar triangles learning exercise, students find the scale factor of 6 sets of similar triangles. Students find the scale factor of two similar triangles given a sketch with measurements. Students use proportions to find a...
Worksheet
Curated OER

Measuring Speed in the Universe

For Students 8th - 10th
In this measuring speed in the universe worksheet, learners use photographs of 3 astronomical phenomena including supernova explosions, coronal mass ejections and solar flare shock waves to find how fast they move. The photographs show...
Worksheet
Houghton Mifflin Harcourt

Similar Polygons and Circles

For Students 9th - 12th
In these similar polygons and circles worksheets, students complete 15 questions including 9 word problems regarding similar polygons. Students then complete 15 questions including 1 word problem involving circumference, area, and arc...
Interactive
CK-12 Foundation

Area and Volume of Similar Solids: Similar Solids

For Students 6th - 12th Standards
Five questions make up an interactive designed to boosts knowledge of area and volume of solid figures. Question types include multiple-choice, true or false, and fill-in-the-blank. A scale model changes measurement to provide a visual...
Instructional Video4:55
Corbett Maths

Finding the Centre of Enlargement

For Students 6th - 12th Standards
Where did the transformation begin? Using a ruler, the narrator of a short presentation shows how to find the center of enlargement for transformed figures. Worksheets provide the class members an opportunity to practice the newly...
Worksheet
Curated OER

Exploring Similar Polygons

For Students 10th
In this exploring similar polygons worksheet, 10th graders solve 9 various problems that are related to similar polygons. First, they define similar and the symbol used to identify similar to another. Then, students find the measurement...
Lesson Plan
Curated OER

How Big is Barbie?

For Teachers 9th - 12th
Students measure various dimensions of a male and a female dolls body and scale them proportionally to average human measurements. They calculate the appropriate scale factor (magnitude) to enlarge their doll and apply that scale factor...
Lesson Plan
EngageNY

Between-Figure and Within-Figure Ratios

For Teachers 9th - 10th Standards
Tie the unit together and see concepts click in your young mathematicians' minds. Scholars apply the properties of similar triangles to find heights of objects. They concentrate on the proportions built with known measures and solve to...
Lesson Plan
Curated OER

Maps

For Teachers 5th - 10th
Students figure out the mileage from one state to another using a map. In this map lesson, students look at the scale factor and turn it into a fraction. They measure the distance between two cities and use the proportion to find the...
Handout
Charleston School District

Identifying Series and Determining Congruence or Similarity

For Students 8th Standards
Learners consider a set of questions to determine a series of transformations that will move one figure to another. Once the series is determined, the pupil then determines whether the pre-image and image are either congruent...
Activity
Illustrative Mathematics

Dilating a Line

For Teachers 9th - 12th Standards
High School geometers verify through experimentation certain properties about dilations. This multi-step problem challenges them to construct examples of dilations to verify specific facts, the final step provides an opportunity to more...
Worksheet
Curated OER

Similarity

For Students 7th - 12th
In this similarity activity, students identify similar shapes.  They determine the scale factor of the similar shapes and find their volume and area.  Students enlarge shapes according to the given scale factor.  They...
Worksheet
Curated OER

Similar Polygons

For Students 9th - 10th
In this geometry worksheet, students solve problems dealing with polygons. They differentiate between similar and congruent polygons. There are 18 questions with an answer key.
Lesson Plan
Curated OER

Perimeter and Area of Similar Figures

For Teachers 8th - 11th
Students explore the relationships between similar figures. In this relationships between similar figures lesson, students discuss relationships between perimeter, circumference, area, surface area, and volume of similar figures through...
Assessment
EngageNY

Mid-Module Assessment Task: Grade 8 Module 3

For Students 8th Standards
How well does the class understand dilations? The three-part assessment presents problems related to the properties of dilations. Pupils perform dilations and determine whether a dilation is responsible for a specific image.
Lesson Plan
EngageNY

Comparing the Ratio Method with the Parallel Method

For Students 9th - 10th Standards
Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...
Assessment
Inside Mathematics

Hopewell Geometry

For Teachers 9th - 12th Standards
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
Assessment
EngageNY

Mid-Module Assessment Task - Geometry (Module 2)

For Students 9th - 10th Standards
Challenge: create an assessment that features higher level thinking from beginning to end. A ready-made test assesses knowledge of dilations using performance tasks. Every question requires a developed written response. 
Worksheet
Curated OER

Unit 14 - Loci and Transformations

For Students 9th - 12th
In this transformations worksheet, students solve 25 short answer problems.  Kids dilate, reflect, and translate points and figures in the coordinate plane.  Students determine scale factors and lines of symmetry of figures.
Lesson Plan
Curated OER

Corresponding Parts of Similar Triangles

For Teachers 9th - 12th Standards
Here is a lesson that has learners take a look at corresponding parts of similar triangles, ratios of similarity, reductions and enlargements. They'll manipulate the scale factor (r) to observe the changes in similar triangles and then...
Lesson Plan
Curated OER

Similarity

For Teachers 6th - 8th
Students engage in a lesson that is concerned with the concept of similarity. This takes higher order thinking skills and being able to separate into categories. Specifically in this lesson they are introduced to the scale and how it is...
Assessment
Mathematics Assessment Project

Photographs

For Teachers 6th - 8th Standards
Picture your pupils using this assessment task. Class members must first determine the measurements of smaller copies of photographs placed next to the original. They then determine the dimensions of the entire sheet of photographs.
Lesson Plan
EngageNY

Properties of Dilations

For Teachers 8th Standards
Investigate dilations to learn more about them. The second segment in a series of 16 provides a discussion of properties of dilations by going through examples. The problem set provides opportunities for scholars to construct dilations.