Curated OER
Similarity and Congruence
Students determine that two figures are similar or congruent by
investigating figures that are similar and figures that are congruent. They prove that two figures are similar or congruent by using definitions,
postulates, and theorems.
Curated OER
The Truth About Triangles And Proofs
Learners engage in a lesson that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the importance of...
Curated OER
Finding Area of Similar Figures
Students explore the concept of finding area of similar figures. In this finding area of similar figures lesson, students use pattern blocks to construct similar figures. Students trace their construction and find the area. Students...
EngageNY
What Are Similarity Transformations, and Why Do We Need Them?
It's time for your young artists to shine! Learners examine images to determine possible similarity transformations. They then provide a sequence of transformations that map one image to the next, or give an explanation why it is not...
Curated OER
Geometry of Triangles Using a Protractor
Seventh graders use a protractor to measure angles and solve a problem involving distance. In this measuring angles with a protractor lesson plan, 7th graders calculate the distance of a line on a diagram by using a protractor to measure...
Curated OER
SAS Similarity Theorem
Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.
Curated OER
Does Your Field Measure Up
Learners measure angles using a plane table kit. In this geometry lesson, students use trigonometric identities to find the values of the length of a football field.
Curated OER
Triangle Inequality Theorem
Students use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...
Curated OER
Investigating Trigonometric Ratios Through Similar Right Triangles
Students identify similar and congruent right triangles. For this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.
Curated OER
Branding Circles, Squares, Rectangles, Triangles
Compare and classify 2-D shapes! Kindergarteners inspect the attributes of plane shapes and examine shapes in everyday life. They label the circles, squares, rectangles, and triangles they find. This is the website where you can find the...
Discovery Education
Discovering Math: Exploring Geometry
Apply geometric properties and formulae for surface area and volume by constructing a three-dimensional model of a city. Learners use similar and congruent figures and transformations to create a city of at least 10 buildings. They trade...
Project Maths
Introduction to Trigonometry
The topic of trigonometric ratios is often covered with loads of rote memorization baked into the activity. This activity set, however, leans more on using similar triangles and discovery learning to help young geometers develop a deeper...
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
Building Congruent Triangles
Students differentiate between congruent and similar triangles. In this geometry lesson, students identify the lengths and angle measures of triangles. They use postulates to prove their answers.
Curated OER
The Sierpinski Triangle
Students investigate the Sierpinski triangle. In this geometry lesson, students define fractal curves and its relationship to triangles. They identify repeating sequences and relate it to fractals.
Curated OER
Similarity and Congruence
Students explore the concept of similarity and congruence. In this similarity and congruence lesson plan, students cut out strips of paper and form a triangle. Students try to prove that their triangles are congruent using the SSS...
Curated OER
Measuring Heights With Triangles
Students identify the different properties of triangles. In this geometry lesson, students differentiate between congruent and similar triangles. They use mathematical reasoning to solve word problems.
Curated OER
Triangle Congruence
Learners use web applet to create congruent triangles. For this geometry lesson, students differentiate between congruent and similar. They create shapes online and drag those shapes around to create visuals of triangles.
Curated OER
Ratios of Similar Figures
Students 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
Congruent Triangles
Students identify properties of triangles. For this geometry lesson, students differentiate between similar and congruent triangles. They use the umber of sides to help define the angle of the polygon.
Curated OER
Congruent and Similar figures
Eighth graders explore congruent and similar figures. For this eighth grade geometry lesson, 8th graders use geoboards to create congruent and similar figures and explore the relationships between the sides and angles.
Illustrative Mathematics
Why Does SSS Work?
While it may seem incredibly obvious to the geometry student that congruent sides make congruent triangles, the proving of this by definition actually takes a bit of work. This exercise steps the class through this kind of proof by...
Curated OER
Triangles in Architecture
Learners find triangles in the real world. For this geometry lesson, students analyze and identify properties of two and three-dimensional objects. They differentiate between similarity and congruence.
Curated OER
Similar Triangles - Geometry Exploration
Eighth graders become engaged in a activity in geometry to improve mathematical skills. They construct triangles, segments, and points using Geometer's Sketchpad to demonstrate how dilations of triangles and rectangles change geometric...