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Worksheet
Curated OER

Quiz: Beginning Congruent Triangle Proofs

For Students 10th - 11th
In this congruent triangle proof worksheet, students write theorems to prove the congruence of given triangles. This one-page worksheet contains three given polygons to prove congruence.
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Worksheet
Curated OER

Indirect Euclidean Proofs

For Students 10th
In this Euclidean proofs activity, 10th graders solve 10 different problems that include completing indirect Euclidean proofs. First, they write a statement for each of the reasons listed on the sheet of proofs. Then, students solve the...
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Worksheet
Curated OER

Identifying Similar Triangles

For Students 10th
In this identifying similar triangles worksheet, 10th graders solve 5 different proofs related to similar triangles. First, they identify the similar triangles in each figure and explain why they are similar, using the information to...
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Worksheet
Curated OER

Triangle worksheets

For Students 10th
In this geometry worksheet, 10th graders explore triangle properties, including the sum of the measures of the angles of a triangle, the triangle inequalities, properties of isosceles triangles, properties of congruent triangles, and...
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Worksheet
Curated OER

Congruent Triangles

For Students 10th
In this geometry learning exercise, 10th graders identify the corresponding parts of congruent triangles.  The one page learning exercise contains four problems.  Answers are not provided. 
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Lesson Plan
Curated OER

Isosceles Triangles

For Teachers 9th - 10th
Young scholars identify the properties of an isosceles triangle. In this geometry instructional activity, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
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Unit Plan
Mathematics Vision Project

Module 6: Congruence, Construction, and Proof

For Teachers 8th - 10th Standards
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This unit...
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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....
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Worksheet
Curated OER

Proofs

For Students 10th
In this proofs worksheet, 10th graders solve and graph 8 different equations. First, they prove that each triangle is either congruent or similar. Then, students use the concept of corresponding parts of congruent triangles to solve each...
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Worksheet
Curated OER

Proofs Involving Congruent Angles

For Students 11th - 12th
For this congruent triangle worksheet, learners write proofs to support characteristics of congruent triangles. This one-page worksheet contains ten problems.
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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...
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Activity
Illustrative Mathematics

Points equidistant from two points in the plane

For Teachers 9th - 12th Standards
Young geometers apply their deductive reasoning skills and knowledge of proving triangles congruent in a task that asks them to prove if a point lies on the perpendicular bisector of a segment, then it is equidistant from the endpoints...
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Worksheet
Mt. San Antonio Collage

The Trapezoid

For Students 9th - 12th Standards
Enjoy this nicely organized worksheet that puts together multiple problems regarding trapezoid proofs. The resource can be used as a guide that begins with proving properties and ends with solving for measures of line segments.
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Worksheet
Curated OER

Euclidean Proofs involving Triangles and Circles (Congruency Proofs)

For Students 10th
In this geometry worksheet, 10th graders focus on Euclidean proofs involving triangles and circles.  The eight page worksheet contains eight proofs.  Solutions are not provided. 
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Worksheet
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Jesuit High School

Geometry Sample Problems

For Students 8th - 11th Standards
I'd like to prove that this instructional activity has a lot to offer. Seven problems using triangles and parallelograms practice the traditional method of a two-column proof. After the instructional activity is some practice problems...
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Lesson Plan
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Illustrative Mathematics

Are They Similar?

For Teachers 9th - 11th Standards
Learners separate things that just appear similar from those that are actually similar. A diagram of triangles is given, and then a variety of geometric characteristics changed and the similarity of the triangles analyzed. Because the...
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Assessment
Inside Mathematics

Rhombuses

For Teachers 9th - 12th Standards
Just what does it take to show two rhombuses are similar? The assessment task asks pupils to develop an argument to show that given quadrilaterals are rhombuses. Class members also use their knowledge of similar triangles to show two...
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Worksheet
Curated OER

Circle Proofs

For Students 10th
In this circle proofs activity, 10th graders complete 4 different problems that include circle proofs. They respond to each of the questions that deal with circle proofs. Then, students read the given information and use the circle...
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Interactive
Curated OER

Proofs with Triangles Self-check Practice

For Students 8th - 10th
In this triangle theorems worksheet, students identify the theorem used to prove the specified triangular relationship. Students are shown an illustration of two or more triangles. They identify the postulate that would be used to prove...
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Worksheet
Curated OER

Properties of Geometry

For Students 10th
In this properties of geometry worksheet, 10th graders solve and complete 12 different problems that include various theorems. First, they draw a figure that illustrates the SAS inequality property. Then, students prove that two line...
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Lesson Plan
Curated OER

NON-EUCLIDEAN GEOMETRY.

For Teachers 8th - 9th
Students study relationships between angles, side lengths, perimeters, areas and volumes of similar objects. In this lesson students also create and critique inductive and deductive arguments concerning congruency, similarity and the...
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Lesson Plan
Curated OER

The Pythagorean Theorem Lesson 2

For Teachers 8th - 12th
Learners discuss and review examples of the Pythagorean Theorem using a GSP, Geometer's Sketchpad, activity.
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Worksheet
Curated OER

Why do Stars Rise in the East?

For Students 8th - 10th
In this stars rise in the east instructional activity, students use geometry to show how the Earth rotates from west to east and why celestial bodies appear to rise in the east and set in the west. Students draw a figure and label given...
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Worksheet
Mt. San Antonio Collage

Properties of a Parallelogram

For Students 9th - 12th Standards
More than just a worksheet, the resource provides a thorough guide to navigate through the land of parallelograms. Filled with definitions and theorems, the resource supports learners through problems such as proofs and finding missing...