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Lesson Plan
Virginia Department of Education

Similar Triangles

For Teachers 9th - 11th Standards
Pupils work in pairs to investigate what it takes to prove that two triangles are similar. They work through various shortcuts to find which are enough to show a similarity relationship between the triangles. Small groups work with the...
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Lesson Plan
EngageNY

Tangent Segments

For Teachers 9th - 12th Standards
What's so special about tangents? Learners first explore how if a circle is tangent to both rays of an angle, then its center is on the angle bisector. They then complete a set of exercises designed to explore further properties and...
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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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Interactive
Curated OER

Arcs and Chords Multiple Choice

For Students 9th - 10th
In this geometry worksheet, students answer questions about triangles using the correct properties. They find missing angles and sides of triangles. There are 15 questions with an answer key.
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Worksheet
Curated OER

Polygons

For Students 10th
For this polygons worksheet, 10th graders identify and define both a polygon and a convex polygon and then, they apply two theorems that involve the interior and exterior angles of a convex polygon. First, they find the sum of the...
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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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Worksheet
Curated OER

Trapezoids

For Students 10th
In this trapezoids worksheet, 10th graders solve 5 different problems related to trapezoids and applying the appropriate theorem. First, they define a trapezoid, including its bases, legs, and base angles. Then, students use the...
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Lesson Plan
Curated OER

Geometry and Measurement

For Teachers 6th - 8th
Students view a right triangle displayed by the teacher. Students measure legs and the interior angles of the triangle. They look for a pattern or relationship between the legs and angles. Students use pegboards and string to create more...
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Printables
Virginia Department of Education

High School Mathematics Geometry Vocabulary Word Wall Cards

For Teachers 9th - 10th
Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...
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Lesson Plan
Curated OER

SuperShapes, Part 1; "Tri"ing Triangles

For Teachers 5th - 6th
An outstanding instructional activity on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about...
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Lesson Plan
Curated OER

Exploring the Hinge Theorem

For Teachers 9th - 10th
Pupils explore the application of Hinge Theorem. In this geometry lesson, students write inequalities, given two sides of a triangle. They solve problems with triangular inequalities using the proper theorem.
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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...
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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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Activity
Curated OER

Inscribing a Square in a Circle

For Teachers 9th - 11th Standards
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
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Worksheet
Curated OER

Similar Polygons Homework

For Students 9th - 10th
In this geometry activity, students solve problems using the similarity and congruent theorem. They find the vertices and different parts of polygons using theorems. There are 18 questions.
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Worksheet
Curated OER

Parallelograms

For Students 10th
In this parallelograms worksheet, 10th graders identify and describe a quadrilateral, a diagonal, and a parallelogram in 7 different problems. First, they find the values of x, y, and z in each quadrilateral to prove that it is a...
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Lesson Plan
Curated OER

Plain Figures and Measuring Figures

For Teachers 10th - 12th
Students investigate basic geometric concepts. For this geometry lesson, students explore solids through measuring and modeling. This assignment models the importance of understanding concrete objects in geometry.      
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Lesson Plan
Curated OER

Math: Arcs and Chords

For Teachers 9th - 10th
Students draw diagrams demonstrating how it is possible to two central angles to be congruent and their minor arcs are not congruent. In groups, they illustrate theorems with their constructed circles, create diameters of circles that...
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Lesson Plan
Curated OER

Indirect Proof and Inequalities in One Triangle

For Teachers 10th
In this geometry worksheet, 10th graders order the sides and angles of a triangle and determine the range of the third side of a triangle given the lengths of two sides.  The one page worksheet contains sixteen questions.  Answers are...
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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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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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Lesson Plan
Curated OER

Similar Triangles - Applied Problems

For Teachers 9th - 12th
Pupils differentiate between similar and congruent triangles. In this geometry lesson, students identify the angles of triangles using the similarity theorem. They apply concepts of triangles to the real world.
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Lesson Plan
Curated OER

Studying Special Segments in Triangles

For Teachers 8th - 10th
Students investigate special segments in triangles. In this geometry lesson, students graph, compare, estimate and predict findings based on their data. They differentiate between similarity and congruence of triangles.
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Lesson Plan
Curated OER

Identifying Lines of Symmetry

For Teachers 8th - 10th
Students calculate the lines of symmetry using polygons. In this geometry lesson, students graph, compare and estimate using collected data. They identify different attributes to the polygons based on their sides.