Willow Tree
Ratios and Proportions with Congruent and Similar Polygons
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...
Flipped Math
Similar Figures
Use some similar problems to find side lengths. Pupils learn the definition of similar figures and how it relates to corresponding angles and sides. Using the definition, individuals calculate the lengths of missing sides and practice...
Scholastic
Study Jams! Similar Figures
Discover how triangles are congruent based on their sides, angles, and proportionality. Learners explore the ways to determine similarity at their own pace, and then they practice afterwards with an assessment.
Concord Consortium
Proportional Representation
Sometimes the solution is all a matter of perspective. The short assessment task presents a problem to pupils that requires them to make sense of a diagram. Once learners see two similar triangles, the rest of the solution is solving a...
EngageNY
Between-Figure and Within-Figure Ratios
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...
EngageNY
Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...
EngageNY
Similarity
Learn similarity through a transformations lens! Individuals examine the effects of transformations and analyze the properties of similarity, and conclude that any image that can be created through transformations is similar. The...
EngageNY
The Side-Angle-Side (SAS) and Side-Side-Side (SSS) Criteria for Two Triangles to Be Similar
Playing with mathematics can invoke curiosity and excitement. As pupils construct triangles with given criteria, they determine the necessary requirements to support similarity. After determining the criteria, they practice...
Inside Mathematics
Rhombuses
Just what does it take to show two rhombuses are similar? The assessment task asks pupils to develop an argument to show that given quadrilaterals are rhombuses. Class members also use their knowledge of similar triangles to show two...
Noyce Foundation
Photographs
Scaling needs to be picture perfect. Pupils use proportional reasoning to find the missing dimension of a photo. Class members determine the sizes of paper needed for two configurations of pictures in the short assessment task.
El Paso Community College
Geometry Definitions
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet.
EngageNY
Linear Equations in Disguise
In the eighth segment of a 33-part unit, learners look at equations that do not appear to be linear at first glance. The equations are proportions where the numerators and denominators may have more than one term. To round out the...
Illustrative Mathematics
Gotham City Taxis
Taxi! Have your travelers figure out how far they can go in a taxi for $10.00. They must account for the mileage rate and tip in their calculation. They can set up a table or make an equation to solve for the exact mileage they can...
Curated OER
7.RP Music Companies, Variation 1
We've got the beat! And your musically-minded mathematicians will tap their toes as they determine which music company would be getting a better deal based on their offers to buy out TunesTown. The topic is extended in an additional...
Flipped Math
Side Splitter Theorem
Apply perspective to similarity. Individuals learn about the Side Splitter Theorem by looking at perspective drawings. Pupils use the theorem and its corollary to find missing lengths in figures. Next, they practice using the theorem and...
Mathed Up!
Area of Sector and Length of Arcs
Viewers learn how to apply proportional reasoning to find area of sectors and arc lengths with a video that starts off explaining how to find the areas of circle sectors and the lengths of arcs. Scholars then practice solving problems...
Inside Mathematics
Hopewell Geometry
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...
CK-12 Foundation
CK-12 Middle School Math Concepts - Grade 6
Twelve chapters cover a multitude of math concepts found in the Common Core standards for sixth grade. Each title provides a brief explanation of what you will find inside the chapter—concepts from which you can click on and learn more...
American Institute of Architects
Architecture: It's Elementary!—First Grade
Build an interest and appreciation for architecture in your young learners with this fun 10-lesson art unit. Engaging children in using their five senses, the class first observes the environment around them, paying...
National Endowment for the Humanities
A Story of Epic Proportions: What Makes a Poem an Epic?
Learners analyze the epic poem form and its roots in oral tradition. For this epic poetry lesson, students research the epic hero cycle and recognize the pattern of events and elements. Learners analyze the patterns embedded in the stories.
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Kenan Fellows
Math Made Simple as 1-2-3: Simplified Educational Approach to Algebra
Writing an equation of a line is as easy as m and b. A lesson presentation gives individuals different strategies for writing equations of lines. Some items provide a slope and a point while others provide two points. Whatever the given,...
Texas Education Agency
Texas Gateway: Generalizing Geometric Properties of Ratios in Similar Figures
Students will investigate patterns to make conjectures about geometric relationships and apply the definition of similarity, in terms of a dilation, to identify similar figures and their proportional sides and congruent corresponding...
PBS
Pbs Learning Media: Scale City: Similar Figures and Unknown Heights in Practice
In this interactive, students explore how to use shadows, proportional reasoning, and similar figures to determine the unknown height of an object. The interactive allows students to explore the proportional relationships among the...