Lesson Plan
EngageNY

What Are Similarity Transformations, and Why Do We Need Them?

For Students 9th - 10th Standards
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...
Interactive
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GeoGebra

Conjectures and Proof

For Students 9th - 12th Standards
Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...
Performance
Radford University

Triangular Irrigation

For Teachers 9th - 12th Standards
Try to keep the pipe short. Learners investigate where to place a water pump to use the least amount of pipe. Scholars use their knowledge of reflections and congruent triangles to find the best location for the water pump. Finally, they...
Lesson Plan
Curated OER

Triangle Proofs

For Teachers 10th
Tenth graders complete a unit of lessons on congruent triangles and triangle proofs. They observe and participate in teacher-led discussions of examples of the methods to prove that triangles are congruent, and create an original proof.
Assessment
Math Worksheets Center

Congruent Triangle Proofs Quiz

For Students 9th - 12th
A congruent triangles quiz challenges teenage mathematicians to complete a pair of geometric proofs. Each problem includes a picture of the triangles in question, a given set of information, and the five steps needed to finish the proof....
Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve 5 problems that relate to different right triangles. First, they find the values of x and y so that each triangle is congruent to the other. Then, students write a two-column proof...
Lesson Plan
Curated OER

Simson Line

For Teachers 9th - 12th
Stuednts identify triangles for the Simson Line. In this geometry lesson, young scholars solve triangular problems using the properties of triangles.They differentiate between the height, congruency and similarity.
Lesson Plan
Curated OER

The Ambiguous Case

For Teachers 9th - 10th
Students investigate the relationship of triangles with its sides and angles. For this geometry lesson, students create visual on the graphing navigator as they study triangles. They move the sides around to create different angle-side...
Activity
1
1
Illustrative Mathematics

Midpoints of the Sides of a Paralellogram

For Teachers 9th - 12th Standards
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 9th - 12th
Students are introduced to the Pythagorean theorem. They use three different activities that give students the opportuntiy to observe triangles, and use the Pythagorean theorem and practice different ways of determining areas of...
Lesson Plan
Curated OER

Pythagorean Theorem by Graphic Manipulation

For Teachers 7th - 9th
There are many different ways to show a proof of the Pythagorean Theorem.  Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...
Instructional Video20:08
2
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Flipped Math

Trig Ratios

For Students 9th - 12th Standards
Take ratios of sides to a new level. Pupils learn the definitions of the three basic trigonometric ratios in right triangles. Using the definitions, scholars find missing lengths in right triangles, based on a known angle. Individuals...
Printables
Virginia Department of Education

High School Mathematics Geometry Vocabulary Word Wall Cards

For Teachers 9th - 10th
Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...
Worksheet
Lane Community College

Review Sheets: Geometry

For Students 8th - 11th
Full of problems with polygons, angles, lines, and triangles, your learners get a multi-page packet that provides all they need to know. It contains many of the standard problem types as well as some more challenging questions. 
Printables
Virginia Department of Education

Middle School Mathematics Vocabulary Word Wall Cards

For Teachers 5th - 9th
Having a good working knowledge of math vocabulary is so important for learners as they progress through different levels of mathematical learning. Here is 125 pages worth of wonderfully constructed vocabulary and concept review cards....
Lesson Plan
Curated OER

An Application of Congruence

For Teachers 9th - 10th
Learners solve triangles using the properties if congruency. In this geometry lesson plan, students apply congruent and similar figures to solve real world and math problems. They show they are able to follow instructions.
Lesson Plan
Pennsylvania Department of Education

Making Triangles

For Teachers Pre-K - 2nd
Students use interactive geoboards to identify simple geometric shapes. In this making triangles lesson, students describe the properties associated with geometric shapes. Students develop spatial sense and the mathematical meaning...
Lesson Plan
Curated OER

TRIANGULATEERS IN THE REAL WORLD

For Teachers 3rd - 6th
Students explore about triangles and the simple machines that are made from those triangles. They are able to identify the kinds of triangles in the machines, tell how the triangular shapes make the machines function, and build a simple...
Lesson Plan
Curated OER

An Introductions to Congruent Polygons

For Teachers 8th - 10th
Students differentiate between similar and congruent polygons. For this geometry lesson, students define the theorems and reasons for polygons similarity and congruence. They are given pictures and patterns to differentiate and identify.
Assessment
Los Angeles County Office of Education

Assessment For The California Mathematics Standards Grade 4

For Students 4th Standards
Have scholars show what they know with a 20-page assessment aligned to the California State Standards. The test covers concepts such as large and whole numbers, all four mathematical operations, fractions, decimals, geometric figures,...
Assessment
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1
Mathematics Assessment Project

College and Career Readiness Mathematics Test A2

For Students 9th - 12th
A six-page evaluation covers material included in algebra, geometry, and algebra II. Applied word problems are mixed in with short answer questions. It also provides questions on mathematical reasoning.
Handout
El Paso Community College

Geometry Definitions

For Students 7th - 9th Standards
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet. 
Worksheet
Curated OER

Exploring Congruent Triangles

For Students 10th
In this congruent triangles worksheet, 10th graders solve 10 different problems related to exploring various types of congruent triangles. First, they label the corresponding parts and use the figures to complete each statement. Then,...
Lesson Plan
Curated OER

Why can't We Use SSA to Prove Triangles Congruent?

For Teachers 9th - 10th
Students investigate triangles and congruences. In this geometry instructional activity, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.