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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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Interactive
Annenberg Foundation

Geometry 3D Shapes: 3D Shapes

For Students 6th - 10th Standards
Explore vocabulary related to three-dimensional shapes. An instructional website describes the characteristics of different geometric solids. Learners can use an interactive component to view nets, faces, vertices, and edges of common...
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Worksheet
Curated OER

Pairs of Lines

For Students 9th - 10th
In this geometry worksheet, students differentiate between perpendicular and parallel planes and lines. They identify segments that are parallel and perpendicular to sides. There are  22 questions.
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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 plan, 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

Geometry Journal: Isosceles Triangles

For Teachers 10th - 12th
In this isosceles triangles worksheet, pupils justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.
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Lesson Plan
Curated OER

Duplicating Segments and Angles

For Teachers 10th
Tenth graders investigate geometric construction.  For this geometry lesson, 10th graders explore the procedure for copying an angle and a segment.  The lesson emphasizes the difference between a sketch, a drawing, and a...
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Worksheet
Curated OER

Quiz: Area of a Circle

For Students 7th - Higher Ed
Geometers test their mastery at finding the area of a circle with 10 basic problems. Circle diagrams show line segments, points, and diameter. Distance of radii are given. They use pi as 3.14 to calculate the area. No answer key is...
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Worksheet
Curated OER

Segments and Rays Homework

For Students 9th - 10th
In this geometry worksheet, learners identify segments and rays using sketches. They sketch intersection to a plane and describe the relationship of the segment and ray as it related to the intersection. There are 15 questions.
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Worksheet
Curated OER

Geometry Review

For Students 5th - 10th
In this math review worksheet, students calculate the mean, median, mode, range, line segments, angles, and standard deviation for number and word problems. Students complete 11 problems.
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Lesson Plan
Curated OER

Geometry and Geoboard

For Teachers 6th
Sixth graders use geoboards and dot paper to experiment with geometric concepts. In this geometry instructional activity, 6th graders complete four activities using geoboards or dot paper including naming points on a coordinate plan and...
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Lesson Plan
Curated OER

Geometry of Triangles Using a Protractor

For Teachers 7th
Seventh graders use a protractor to measure angles and solve a problem involving distance. In this measuring angles with a protractor lesson plan, 7th graders calculate the distance of a line on a diagram by using a protractor to measure...
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Lesson Plan
Curated OER

Human Geometry Book

For Teachers 3rd - 5th
Students investigate geometric shapes. In this geometry lesson, students read the book The Greedy Triangle and define the shapes mentioned in the book. Students make the shapes by using their bodies.
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Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
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Worksheet
Curated OER

Arcs and Chords Homework

For Students 9th - 12th
For this geometry worksheet, students examine a circle with chords and apply formulas to solve for the missing segments or arc. There are 9 questions.
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Lesson Plan
Illustrative Mathematics

Two Wheels and a Belt

For Teachers 9th - 10th Standards
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
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Assessment
EngageNY

Mid-Module Assessment Task - Geometry (Module 2)

For Students 9th - 10th Standards
Challenge: create an assessment that features higher level thinking from beginning to end. A ready-made test assesses knowledge of dilations using performance tasks. Every question requires a developed written response. 
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Lesson Plan
1
1
Illustrative Mathematics

Placing a Fire Hydrant

For Teachers 9th - 10th Standards
Triangle centers and the segments that create them easily become an exercise in memorization, without the help of engaging applications like this lesson. Here the class investigates the measure of center that is equidistant to the three...
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Assessment
Concord Consortium

Divisions

For Students 7th - 12th Standards
Divide and conquer the geometry problem. Young scholars consider how to subdivide triangles into smaller ones that have equal areas. They must apply their knowledge of medians to help accomplish the task.
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Worksheet
Curated OER

Building Blocks of Geometry

For Students 9th - 11th
In this geometry worksheet, students answer questions about midpoints, distance, lines and segments. They are given different shapes and asked to calculate the angles, and sides of polygons.
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Lesson Plan
Curated OER

Investigating Segments in a Right Triangle

For Teachers 9th - 12th Standards
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
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Lesson Plan
Curated OER

Properties of Lines - Parallel and Perpendicular

For Teachers 6th
Sixth graders identify parallel and perpendicular lines in the alphabet. For this line properties lesson, 6th graders use the letters of the alphabet to show parallel and perpendicular lines. Students open a Geogrid Mat on the computer...
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Lesson Plan
Curated OER

Perpendicular Segments in a Circle

For Teachers 9th - 12th Standards
High schoolers explore the concept of circles as they construct a circle using a program such as Cabri Jr. Learners construct a chord and a diameter that are perpendicular, then measure the bisected chord and notice that both sides of...
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Worksheet
Curated OER

Perpendicular Bisector

For Students 10th - 12th
In this perpendicular bisector activity, students fold paper, according to instructions, to discover the perpendicular bisector of a segment.  They explore the distances from the bisector to the endpoints of a specified...
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Worksheet
Curated OER

Challenge: Skills and Applications Lesson 1.3

For Students 10th - 12th
In this skills instructional activity, learners explain the Segment Addition Postulate, provide examples and counter examples and determine congruent line segments.  This one-page instructional activity contains 11 multi-step problems.