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...
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.
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 plan, have your class construct similar triangles using Cabri Jr so that they share a common...
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...
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
Corresponding Parts of Similar Triangles
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...
Curated OER
Similarity and Dilations - Discover Properties of Similar Figures
Learners investigate properties of similar figures. In this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...
Curated OER
Nested Similar Triangles
Nested triangles have been created so that they share a common vertex and vertex angle. Learners drag the endpoints of the side that is opposite the common angle to discover the conditions that make the nested triangles similar. When...
Curated OER
Similar Triangles - Applied Problems
High schoolers differentiate between similar and congruent triangles. In this geometry instructional activity, students identify the angles of triangles using the similarity theorem. They apply concepts of triangles to the real world.
Curated OER
Similar Triangles
Students differentiate between similar and congruent triangles. For this geometry lesson, students identify the missing side and angle of a triangle. They identify the different ratio and proportion of the sides of a triangle.
Virginia Department of Education
Similar Figures
How similar do figures have to be to be similar figures? Individuals learn to identify similar figures by verifying that angles are congruent and sides are proportional. Additionally, they match the corresponding parts of similar figures.
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...
101 Questions
Square Partitions
Challenge your classes while developing their problem-solving skills. A square is divided neatly into four equal triangles by its diagonals until one diagonal is moved from a vertex to the midpoint of one side. Now, scholars must devise...
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...
Curated OER
Triangle Midsegment
Learn how to calculate the length and midsegments of triangles. Learners differentiate between similar and congruent triangles. They create a spreadsheet with their findings.
Curated OER
Angles and Similarity
High schoolers identify triangles as similar or congruent. In this geometry lesson, students drag triangles around on the navigator to see the effect of different angles on the shape of the triangle. They discuss angle similarity and...
Curated OER
Ratios of Similar Figures
High schoolers identify the ratios of different triangles. In this geometry lesson, students identify the similarity and differences of triangles. They use the navigator to move the sides of the triangle around.
Curated OER
Similarity and Congruence
Pupils explore the concept of similarity and congruence. In this similarity and congruence lesson, students cut out strips of paper and form a triangle. Pupils try to prove that their triangles are congruent using the SSS theorem of...
Curated OER
Using Cabri Geometry to Create Fractals
Learners construct the Sierpinski Triangle using Cabri Jr. They use a step-by-step guide to construct the Sierpinski Triangle on their graphing calculator and then discuss the formula for constructing a nth stage Sierpinski Triangle.
Curated OER
Proportional Similarities
Young scholars model the geometric relationship with graphing. In this geometry lesson, students differentiate between parallel, perpendicular, similar and congruent shapes. They use properties of polygons to differentiate their...
Curated OER
Dihedral Figures
Middle and high schoolers perform transformations. In this web based activity, students explore dihedral figures. They use the web tools to translate, rotate, and reflect figures. Pupils identify lines of symmetry.
Curated OER
Side Splitter Triangles
Students investigate the side splitter theorem. In this geometry lesson, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.
Curated OER
Soda Cans
Students identify and use properties of similar figures. In this geometry lesson, students use proportions of the sides of triangles to solve triangular relationships. They use soda can as their visuals.
Curated OER
Congruence with Robot Gobot
Students identify the properties of solids and polygons. In this geometry instructional activity, students identify the different measurements of a triangle. They use congruence parts and theorem to prove their answer.