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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers All
Pupils explore how the Pythagorean Theorem works and how to apply it.
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Lesson Plan
Curated OER

Similarity and Congruence

For Teachers 9th - 12th
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...
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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 9th - 12th
Young scholars identify a right angle and right triangle. They perform WebQuests searching for similar figures and solve for the length of one of the sides given the other two.
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Worksheet
Curated OER

Geometry Worksheet: Pythagoras' Theorem

For Students 6th - 8th Standards
In this Pythagorean Theorem worksheet, students use the Pythagorean Theorem to find the length of the unlabeled side of the right triangle. There are 8 problems all together.
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Lesson Plan
Curated OER

Similar Triangles

For Teachers 9th
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.
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Worksheet
Curated OER

Pythagoras' Theorem

For Students 8th - 9th
In this Pythagorean Theorem worksheet, students use the Pythagorean Theorem to determine the length of a missing side. They calculate surface area of a prism. This two-page worksheet contains 4 multi-step problems.
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Lesson Plan
Curated OER

Triangles in Architecture

For Teachers 10th - 12th
Students find triangles in the real world. In this geometry lesson, students analyze and identify properties of two and three-dimensional objects. They differentiate between similarity and congruence.
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Lesson Plan
Futures Channel

Folding Circles

For Teachers 7th - 12th Standards
Students investigate properties of circles. In this geometry lesson, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
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Lesson Plan
Curated OER

Analyzing Congruence Proofs

For Teachers 9th - 12th Standards
Looking at numerous examples of triangles, each with different properties, geometers develop their understanding of congruency. They use the notation of a counter-example to disprove certain conjectures and prove geometric theorems and...
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Interactive
CK-12 Foundation

Basic Trigonometric Functions: Ladder Length

For Students 9th - 12th Standards
Climb the ladder to trigonometry. The interactive introduces trigonometric ratios and finding lengths of sides of right triangles created by a ladder and a building. Learners use the interactive to create triangles by moving the top of...
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Activity
Illustrative Mathematics

Solar Eclipse

For Teachers 9th - 11th Standards
Learners take on the role of astronomers, calculating conditions necessary for a total solar eclipse. Concepts of similar triangles and properties of circles come together as pupils create ratios and use real measurements in determining...
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Worksheet
Curated OER

Triangle Congruence

For Students 10th
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...
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Lesson Plan
Curated OER

Geometric Applications

For Teachers 8th - 9th
In this geometry worksheet, students solve 5 word problems. Each of the problems involves finding one side of a right triangle. Story problems relate the Pythagorean Theorem to building ramps, shadows, and the length of a banner.
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Unit Plan
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EngageNY

Congruence, Proof, and Constructions

For Teachers 8th - 10th Standards
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs.  Each of the almost-forty lessons is broken...
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Lesson Plan
1
1
Curated OER

Areas of Geometric Shapes with the Same Perimeter

For Teachers 7th - 9th Standards
A triangle, square, hexagon, and circle all have a perimeter of one unit. Eighth graders must attempt to find the area of each and arrange them in order from least to greatest areas. A terrific task for applying four different area...
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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. 
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Lesson Plan
Curated OER

Side Splitter Triangles

For Teachers 8th - 11th
Students investigate the side splitter theorem. In this geometry lesson plan, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.
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Lesson Plan
Curated OER

CSI Investigation of Congruence and Similarity

For Teachers 9th - 12th
Students differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
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Lesson Plan
Curated OER

Building Congruent Triangles

For Teachers K - 12th
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.
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Worksheet
Curated OER

Similar Polygons Multiple Choice

For Students 9th - 10th
In this geometry worksheet, students differentiate between similarity and congruence. They find the correct answer using the theorems of similarity and congruence. There are 5 questions with an answer key.
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Lesson Plan
Curated OER

Exploring Characteristics Needed to Prove Two Trianlges Congruent

For Teachers 10th
Tenth graders explore congruent triangles.  In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent.  The lesson combines dry erase board activities and the use of technology.
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Lesson Plan
EngageNY

Criterion for Perpendicularity

For Students 9th - 12th Standards
The Pythagorean Theorem is a geometry pupil's best friend! Learners explain the equation a1b1 + a2b2 = 0 for perpendicular segments using the Pythagorean Theorem. They are able to identify perpendicular segments using their endpoints and...
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Activity
Teach Engineering

Catching the Perfect SAR Waves!

For Students 9th - 11th
Zero in on an interesting resource involving radar technology. Groups construct a radar sensing unit and learn to calibrate the system. Using the radar system and the Pythagorean Theorem, they calculate distances between objects.
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Lesson Plan
EngageNY

General Pyramids and Cones and Their Cross-Sections

For Teachers 9th - 10th Standards
Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...