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Lesson Plan
Curated OER

Isosceles Triangle Theorem

For Teachers 8th - 9th
In this geometry worksheet, students differentiate between isosceles and regular triangles. They calculate the area and perimeter of the triangle. There are eleven questions with an answer key.
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Lesson Plan
EngageNY

Properties of Parallelograms

For Teachers 9th - 10th Standards
Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...
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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
Curated OER

Congruent Trianges - Is This Enough Information?

For Teachers 7th
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.
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Lesson Plan
Curated OER

Congruent Triangles

For Teachers 9th - 12th
Students explore the concept of congruent triangles.  In this congruent triangles lesson, students use Cabri Jr. to construct two congruent triangles using circles.  Students determine if the two triangles are congruent by using the SSS,...
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Lesson Plan
Curated OER

The Truth About Triangles And Proofs

For Teachers 9th - 12th
Students engage in a lesson plan 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...
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Lesson Plan
Curated OER

Study Buddies: Congruent Figures

For Teachers 2nd - 3rd
In this math worksheet, students will work with a coach to determine which shapes (in a box of shapes) are congruent. Students will follow a step-by-step process and notes are provided for the coach.
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Worksheet
Curated OER

Hands On: Construct Triangles and Rectangles

For Students 4th - 7th
In this congruent triangles and rectangles worksheet, students solve 6 word problems where they identify whether triangles and rectangles are congruent, and construct triangles. Students must explain their reasoning and prove each answer.
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Worksheet
Curated OER

Right Triangle congruence

For Students 9th - 10th
Students will determine if two triangles are congruent and which property is used. In this lesson on right triangles, students will determine what additional information is need to make a pair of triangles congruent.
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Worksheet
Curated OER

Transformations and Congruence

For Students 10th
In this transformations and congruence learning exercise, 10th graders solve and complete 5 different types of problems. First, they calculate the length of a line giving their answer in 3 significant figures. Then, students prove that...
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Lesson Plan
Curated OER

Corresponding Parts of Congruent Triangles

For Teachers 9th - 10th
Students identify different parts of a triangle. In this geometry lesson, students differentiate between similar and congruent triangles. They use the navigator to crate a visual of the different parts of a triangle.
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Worksheet
Curated OER

Area of Right Triangles

For Students 8th - 10th
In this are of right triangles worksheet, students read graphs and explore congruent triangles.  They find the area of rectangles and of right triangles.  This one-page worksheet contains explanations, instructions, and 8 problems.
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Worksheet
Curated OER

Special Triangles and Quadrilaterals

For Students 9th - 11th
In this special triangles worksheet, students examine given special triangles.  They determine the length of a missing side and/or the measurement of a missing angle for given triangles and quadrilaterals.  Students justify their answers...
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Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve and complete 23 various types of problems. First, they match the triangle description with the most specific name and write the letter on the line provided. Then, students classify the...
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Lesson Plan
Curated OER

Indirect Measurement with Similar Triangles

For Teachers 9th - 12th
Students use similar triangles to find missing heights.  In this using similar triangles to find missing heights instructional activity, students use proportions to find the heights of missing side lengths.  Students find the height of...
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Worksheet
Curated OER

Triangle Similarity

For Students 10th
In this triangle similarity learning exercise, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles...
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Lesson Plan
Curated OER

Nested Similar Triangles

For Teachers 9th - 12th Standards
Nested triangles have been created so that they share a common vertex and vertex angle. Learners drag the endpoints of the side that is opposite the common angle to discover the conditions that make the nested triangles similar. When...
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Worksheet
Curated OER

Properties of Angles, Lines, and Triangles

For Students 10th
In this properties of angles, lines and triangles instructional activity, 10th graders solve and complete 28 different problems that include determining the measurement of various figures shown. First, they use the geometric properties...
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Lesson Plan
Curated OER

Symmetry, Similar & Congruent Shapes

For Teachers 5th
Fifth graders identify lines of symmetry., similar and congruent shapes. They use construction paper to create their own symmetrical shapes. Students create stained glass frames containing symmetrical, congruent and similar shapes.
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Lesson Plan
Curated OER

Angles, Triangles, Quadrilaterals, Circles and Related

For Teachers 6th - 8th
Students classify angles. In this angles lesson, students explore the characteristics of angles, triangles, quadrilaterals and circles. They identify polygons and sing a classifying angles song. Students participate in a manipulative...
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Lesson Plan
Curated OER

Triangle Midsegment

For Teachers 9th - 12th Standards
Learn how to calculate the length and midsegments of triangles. Students differentiate between similar and congruent triangles. They create a spreadsheet with their findings.
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Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve and complete 14 various types of problems. First, they find the perimeter of the isosceles trapezoid shown. Then, students find the measures of each marked side of a right triangle....
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Worksheet
Curated OER

A Geometry Worksheet - Similar Triangles

For Students 9th - 12th Standards
In this similar triangles worksheet, students find the scale factor of 6 sets of similar triangles. Students find the scale factor of two similar triangles given a sketch with measurements. Students use proportions to find a missing side...
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Worksheet
Curated OER

Proving Triangles Congruent

For Students 10th
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...