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Worksheet
Curated OER

Congruence of Triangles

For Students 10th
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...
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Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 7th - 9th
Learners identify properties of triangles. In this geometry lesson plan, students create triangles using three different segments. They make conjectures and predictions.
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Worksheet
Curated OER

Proofs

For Students 8th - 11th
In this geometric proof worksheet, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use given...
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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. 
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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

Proportional Segments Between Parallel Lines

For Teachers 9th - 12th
Students identify similar triangles.  In this proportional segments lesson, students identify corresponding sides, set up ratios, and find the length of the missing side of a triangle.  They use the parallel/proportionality conjecture to...
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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...
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Worksheet
Curated OER

Exploring Similar Polygons

For Students 10th
In this exploring similar polygons worksheet, 10th graders solve 9 various types of problems related to determining whether each polygon is similar or not. First, they write 3 equal ratios to show corresponding sides are proportional to...
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Lesson Plan
Curated OER

Congruent Triangles

For Teachers 10th
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. 
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Lesson Plan
EngageNY

Between-Figure and Within-Figure Ratios

For Teachers 9th - 10th Standards
Tie the unit together and see concepts click in your young mathematicians' minds. Scholars apply the properties of similar triangles to find heights of objects. They concentrate on the proportions built with known measures and solve to...
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Worksheet
Curated OER

Leveled Problem Solving Areas of Triangles and Trapezoids

For Students 6th
In this geometry worksheet, 6th graders calculate the area of triangles and trapezoids using the given formulas. They use the formulas to find measurements of lines that are part of the triangles and trapezoids.
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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 instructional activity, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.
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Lesson Plan
Curated OER

Optical Illusion

For Teachers 8th - 10th
Students practice creating optical illusions as well as discerning how perception of information may change its characteristics. They distinguish between an equilateral triangle, endpoints, vertices's, and segments of triangles. The...
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Lesson Plan
Curated OER

Geometry Practice: Area of Polygons #8

For Teachers 9th - 12th
In this area of polygons worksheet, students solve 7 short answer and multiple choice questions about area.  Students find the area of triangles given base and height, or points in the coordinate plane.
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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
Willow Tree

Ratios and Proportions with Congruent and Similar Polygons

For Students 8th - 11th Standards
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...
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Assessment
Inside Mathematics

Hopewell Geometry

For Teachers 9th - 12th Standards
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
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Lesson Plan
Willow Tree

The Pythagorean Theorem

For Students 8th - 11th Standards
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...
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Assessment
Noyce Foundation

Parallelogram

For Teachers 6th - 7th Standards
Parallelograms are pairs of triangles all the way around. Pupils measure to determine the area and perimeter of a parallelogram. They then find the area of the tirangles formed by drawing a diagonal of the parallelogram and compare their...
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Printables
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1
Houghton Mifflin Harcourt

Unit 6 Math Vocabulary Cards (Grade 5)

For Students 5th Standards
Acute angles, nets, and vertices are only a few terms that a set of flash cards includes. Among the 108 cards, two types are available; word cards printed in bold-faced lettering, and corresponding definition cards equipped with an...
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Lesson Plan
Curated OER

Triangle Sum Theorem

For Teachers 10th
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...
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Lesson Plan
Curated OER

Simply Similar at Sea: Simple Triangles

For Teachers 10th
Tenth graders answer a variety of problems based on similar triangle and learn about the rule of thumb. They will test the rule of thumb by estimating the distance to an object in the classroom.
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Lesson Plan
Curated OER

Congruent Triangles - Is This Enough Information?

For Teachers 7th
Seventh graders examine congruence postulates and apply knowledge to triangles in the world around them.
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Unit Plan
Mathematics Vision Project

Geometric Figures

For Teachers 10th - 12th Standards
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...