West Contra Costa Unified School District
Investigating Similar Triangles
Let your use of the resource be in proportion to its usefulness. Pupils investigate similar triangles by measuring side lengths and considering given angle measures. The results of the investigation help develop generalizations about...
Curated OER
Unit 5: Worksheet 3 - Similar Triangles
In this similar triangles worksheet, students use proportions to solve for the missing sides of similar triangles. This two-page worksheet contains 16 multi-step problems.
EngageNY
More About Similar Triangles
Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...
Virginia Department of Education
Similar Triangles
Pupils work in pairs to investigate what it takes to prove that two triangles are similar. They work through various shortcuts to find which are enough to show a similarity relationship between the triangles. Small groups work with the...
Education Development Center
Similar Triangles
Model geometric concepts through a hands-on approach. Learners apply similar triangle relationships to solve for an unknown side length. Before they find the solution, they describe the transformation to help identify corresponding sides.
EngageNY
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...
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...
Curated OER
Kuta Software - Infinite Geometry: Similar Triangles
In this similar triangles worksheet, students solve 20 short answer problems. Students determine if two given triangles are similar. Students determine the type of similarity given two triangles. Students are given a sketch of the...
Curated OER
Similar Triangles and Proportions
Pupils investigate similar triangles and proportions as they make conjectures about the length of sides of similar triangles. For this lesson, have your class construct similar triangles using Cabri Jr so that they share a common vertex.
Curated OER
Indirect Measurement with Similar Triangles
Young scholars 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. Young scholars find the height of trees...
Curated OER
A Geometry Worksheet - Similar Triangles
In this similar triangles activity, 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 missing side...
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.
Curated OER
Measurement of Objects Using Similar Triangles in The Plane
Students use similar triangles and a sight tool to find the height and distance between large objects. In this similar triangles lesson plan, students use a constructed sight tool to measure the distance and height of an object using an...
EngageNY
Modeling Using Similarity
How do you find the lengths of items that cannot be directly measured? The 13th installment in a series of 16 has pupils use the similarity content learned in an earlier resource to solve real-world problems. Class members determine...
Curated OER
Chapter 8 Extra Problems Worksheet: Similar Triangles
In this similar triangles worksheet, students solve 6 similar triangles. Students use proportions to solve similar triangles and similar rectangles.
Curated OER
Similar Triangles
Tenth graders practice solving proportions from similar triangles. They watch a PowerPoint presentation and complete a worksheet each of two days of this lesson. Links for worksheets and PowerPoint presentations are included with this...
Curated OER
Glencoe - Proportions and Similar Triangles
In this proportions and similar triangles learning exercise, students solve 14 multiple choice problems. Students find unknown sides of similar triangles using proportions. Students multiply means and extremes to solve proportions.
Mathematics Vision Project
Similarity and Right Triangle Trigonometry
Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...
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...
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...
Curated OER
Similarity: Instructional
In this similarity learning exercise, students solve and complete 7 different problems that include determining various dimensions of mirrors shown. First, they find the length of the diagonal of the large mirror in the diagram. Then,...
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.
Curated OER
Understanding Proportions and Scale Drawings
Proportions are ratios found using multiplication or division. Middle schoolers solve measurement problems, find a figure's missing dimension, and find the distance between two points. Resource features four lesson plans with detailed...
Curated OER
Identifying Similar Triangles
In this identifying similar triangles worksheet, 10th graders solve 6 different types of problem that include identifying and comparing similar triangles. First, they identify the three ways that determine whether two triangles are...