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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 instructional activity, students cut out strips of paper and form a triangle. Students try to prove that their triangles are congruent using the...
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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 9th - 12th
Students 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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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
Young scholars investigate properties of circles. For 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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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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Interactive
CK-12 Foundation

Pythagorean Theorem to Determine Distance: Ladders

For Students 8th - 12th Standards
Young mathematicians to the rescue! Pupils use an interactive to find lengths relating a ladder against a building. The problems involve determining how long a ladder must be to reach a given floor to what floor can a given ladder reach.
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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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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
Curated OER

Similar Triangles on the Coordinate Plane

For Teachers 9th - 10th
Pupils investigate triangles and their properties. In this geometry lesson, students differentiate between similar and congruent triangles. They use the SSS theorem to help identify the triangles that are similar or congruent.
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Assessment10:41
Mathed Up!

Angles: Parallel Lines

For Students 9th - 11th Standards
Viewers are presented with seven problems with parallel lines and angle relationships and must use the given information to find the measures of specific angles. To finish, they explain their process in finding the measures in the problems.
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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 instructional activity, 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

Investigating Trigonometric Ratios Through Similar Right Triangles.

For Teachers 8th - 10th
49Students investigate the properties of right triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
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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 lesson, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.
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Lesson Plan
Curated OER

Pedal Triangles

For Teachers 8th - 10th
Students identify the properties and theorems of triangles. In this geometry lesson, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
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Lesson Plan
Curated OER

Investigating the Sierpinski Triangle

For Teachers 9th - 11th
Students solve and analyze the sierpinski's triangle. In this geometry lesson, students identify properties and theorem of triangles. They solve problems involving angles and sides of triangles.
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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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Lesson Plan
Mathematics Assessment Project

Evaluating Statements About Length and Area

For Teachers 9th - 12th Standards
Class members complete an assessment task by identifying whether statements about triangles and quadrilaterals are always true, sometimes true, or never true. They then participate in a sorting activity with the same objective.
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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...