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...
Massachusetts Department of Education
Similarity through Transformations
Create the ultimate miniature golf course. The 93-page model curriculum unit from the Massachusetts Department of Elementary and Secondary Education contains nine lessons on understanding similarity in terms of both Euclidean geometry...
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
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...
Curated OER
Similar Figures
Your class will use a TI calculator to drag vertices of rectangles and triangles to observe what happens to ratios of pairs of sides within each figure. They will apply the definition of similarity to identify similar shapes. The lesson...
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...
Curated OER
Triangle Similarity
In this triangle similarity learning exercise, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles...
Curated OER
Exploring Congruent Triangles
In this congruent triangles instructional activity, students solve 12 different equations related to writing a correspondence statement for triangles in the given diagrams. They complete each correspondence statement and write a...
Curated OER
Corresponding Sides and Angles of Similar Triangles
Young scholars differentiate between corresponding sides ad angles of two triangles. In this geometry lesson, students identify the differences as well as the similarities between two triangles. They differentiate between similar and...
EngageNY
Fundamental Theorem of Similarity (FTS)
How do dilated line segments relate? Lead the class in an activity to determine the relationship between line segments and their dilated images. In the fourth section in a unit of 16, pupils discover the dilated line...
Curated OER
Angular Size and Similar Triangles
In this angular size and similar triangles worksheet, students use the properties of similar triangles and the ratios of sides to solve for unknowns in given diagrams.
Math Mammoth
Polygons
In this polygon activity, students identify similar polygons and corresponding sides. They use a compass and ruler to construct polygons, determine the sum of the angles in a given polygon. There are 4 multi-step problems in this...
Curated OER
Indirect Measurement with Similar Triangles
Students use similar triangles to find missing heights. In this using similar triangles to find missing heights lesson, students use proportions to find the heights of missing side lengths. Students find the height of trees...
Everyday Mathematics
Mathematics Within: Slope and Triangles
Learners discover a method for determining the slope of a line by creating and comparing similar triangles. They fold coordinate grids to make three similar triangles then measure the sides to compare the relationships between the...
EngageNY
Congruence, Proof, and Constructions
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs. Each of the almost-forty lessons...
Utah Education Network (UEN)
Finding Missing Lengths of Similar Triangles
Middle and high schoolers explore the properties of similar triangles. In this geometry lesson, pupils play a similarity basketball game, sketch similar triangles, and find the missing measures of similar figures. They find the height of...
Houghton Mifflin Harcourt
Unit 5 Math Vocabulary Cards (Grade 6)
Acute angle, line of symmetry, and vertex are a few terms you'll find in a set of 90 flashcards designed to reinforce math vocabulary. Included in the set are two types of cards; a word card printed in bold font, and a...
Curated OER
Similar Figures
In this similar figures instructional activity, students identify the meaning of similar, corresponding sides, and congruent. They use proportions to find the length of a missing side. Students dilate given figures according...
Curated OER
Proportional Segments Between Parallel Lines
Students identify similar triangles. In this proportional segments lesson, students identify corresponding sides, set up ratios, and find the length of the missing side of a triangle. They use the parallel/proportionality...
Curated OER
Exploring Characteristics Needed to Prove Two Trianlges Congruent
Tenth graders explore congruent triangles. In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent. The lesson combines dry erase board activities and the use of technology.
Curated OER
Identify Similar Figures
Students explore the concept of similar figures. For this similar figures lesson, students develop the idea that similar figures are a different size but the same shape by comparing similar rectangles. Students use patty paper to trace...
Curated OER
Exploring Similar Figures
For this similar figures worksheet, 10th graders solve and measure 10 different angles that are similar. First, they determine which angel corresponds to each given angle. Then, students determine the scale factor of a particular...
Curated OER
Exploring Similar Polygons
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...
Curated OER
Similar Figures
In this similar figures worksheet, students solve and complete 4 different problems. First, they write a proportion and substitute. Then, students find the cross products and simplify. Finally, they divide each side to find the value in...