Illustrative Mathematics
Are They Similar?
Learners separate things that just appear similar from those that are actually similar. A diagram of triangles is given, and then a variety of geometric characteristics changed and the similarity of the triangles analyzed. Because the...
Virginia Department of Education
Pythagorean Theorem
Investigate the meaning of the Pythagorean Theorem through modeling. After comparing the area of the square of each side, individuals cut triangles and squares to facilitate the comparison.
Curated OER
Congruence of Triangles
In this congruence of triangles worksheet, 10th graders solve 10 different problems that include determining the congruence of various triangles. First, they determine the length of two sides of a congruent triangle. Then, students...
Curated OER
Dizzy Heights
Fifth graders explore ways to measure the height of an inaccessible object. They measure lengths using a tape measure or ruler. Students measure angles using a protractor and estimate heights.
West Contra Costa Unified School District
Congruent and Similar Polygons
What's similar about congruent and similar polygons? Young mathematicians first measure the side lengths and angles of given figures. They use these measurements to determine relationships between side lengths and angles of congruent and...
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...
Willow Tree
The Pythagorean Theorem
There isn't a more popular geometry formula than the Pythagorean Theorem! Learners understand the special side relationships in a right triangle. They use the Pythagorean Theorem to find missing sides and to solve problems. They begin...
Curated OER
Finding the Area of an Equilateral Triangle
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...
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...
Houghton Mifflin Harcourt
Unit 7 Math Vocabulary Cards (Grade 6)
Thirty-eight flashcards make up a set designed to reinforce math vocabulary. Two types of cards can be found here; a word card in bold lettering, and a corresponding definition card that offers a labeled example. Terms include area,...
Utah Education Network (UEN)
It's All Just Similar to Me
Middle schoolers explore the concept of similar figures. In this similar figures lesson, pupils calculate scale factors of similar triangles. They find missing sides of triangles, and measure angles using protractors and measure sides of...
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...
Curated OER
Identify Similar Figures
Students explore the concept of similar figures. In this similar figures activity, students develop the idea that similar figures are a different size but the same shape by comparing similar rectangles. Students use patty paper to...
Curated OER
Proving Triangles Congruent
In this proving triangles congruent worksheet, 10th graders solve 5 different problems that include proofs and proving congruence in triangles. First, they determine which postulate can be used to prove the triangles congruent and mark...
Curated OER
Triangle Congruence
In this triangle congruence worksheet, 10th graders solve 12 different problems that include determining triangle congruence. First, they prove that triangles are either congruent or similar. Then, students determine whether they can...
Curated OER
Similarity
Students find the factor of proportionality in similar polygons. In this similarity of polygons lesson plan, students measure the sides and angles of polygons and derive a factor of proportionality between corresponding pairs of sides...
Virginia Department of Education
Congruent Triangles
Is this enough to show the two triangles are congruent? Small groups work through different combinations of constructing triangles from congruent parts to determine which combinations create only congruent triangles. Participants use the...
Curated OER
Using Technology To Teach Parallel Lines With Transversals
Learners explore the relationships between angles formed by two lines cut by a transversal when lines are and are not parallel. They define key vocabulary terms, then using a camera take pictures at their school of parallel lines with...
Curated OER
Triangle Sum Theorem
Tenth graders investigate the theorems of angles and lines to prove triagle sum theorem. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two...
Curated OER
Congruent Triangles
For this congruent triangles worksheet, 10th graders solve and complete 16 different types of problems. First, they name the corresponding parts of the congruent triangles shown and draw a picture. Then, students list the five ways to...
Curated OER
Congruent Trianges - Is This Enough Information?
Seventh graders determine whether two triangles are congruent and provide an explanation to why they are not. They apply concepts of measurement of angles and collect evidence of congruent angles in the world.
Curated OER
Congruent Triangles
Tenth graders explore congruent triangles. In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles are congruent by SSS, ASA, AAS, or SAS.
Curated OER
Similar Triangles
Ninth graders find the height of every day objects using techniques learned through postulates that allow triangles in a problem to be similar. They calculate the length of a missing side and solve proportions.
Curated OER
Investigating Area and Perimeter of Polygons.
Student sinvestigate the area and perimeter of polygons. They differentiate between similar and congruent polygons.. They identify the ratio and proportions of the sides and angles of polygons.