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Lesson Plan
Curated OER

Special Segments in Triangles

For Teachers 9th - 12th Standards
Students identify important properties of triangles. In this geometry instructional activity, students differentiate between medians, bisectors and altitudes in a triangle. They identify the properties of these important segments.
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Lesson Plan
Curated OER

Constructing Perpendicular Bisectors

For Teachers 10th
Tenth graders investigate parallel lines and the angles formed when cut by a transversal. In this geometry lesson, 10th graders construct perpendicular lines and discuss midpoint, segments and perpendicular bisectors. They relate...
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Lesson Plan
Curated OER

IGD: Perpendicular Bisector

For Teachers 9th - 12th
Students draw perpendicular bisectors.  In this perpendicular bisectors lesson, students identify the perpendicular bisector in a polygon.  They use web tools to create and measure perpendicular bisectors.  Students identify lines of...
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Worksheet
Curated OER

Special Segments is a Triangle

For Students 10th
In this geometry worksheet, 10th graders examine the special segments that occur in a triangle.  The three page worksheet contains twenty-five problems.  Answers are not included. 
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Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve 3 extensive informal geometry problems that involve triangles. First, they sketch a triangle, selecting 3 of the sides and constructing 3 midpoints. Students then draw each of 3 medians by...
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Lesson Plan
Curated OER

Inscribed Angles

For Teachers 9th - 10th
Students calculate the inscribed angle of a triangle. In this geometry lesson, students identify the angle created by intersection of a triangle and a circle. They see the relationship between the arc and the angle.
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Lesson Plan
Curated OER

Perpendicular Bisector of a Line Segment

For Teachers 9th - 12th Standards
High Schoolers investigate the perpendicular bisector of a line segment. They use Cabri Jr. to construct the perpendicular bisector of a segment. The dynamics capabilities of Cabri Jr. allow your learners to observe the lengths of the...
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Worksheet
Curated OER

Construct, Bisect, Duplicate: Geometry Practice with Compass and Straight Edge

For Students 9th - 12th
Geometers employ a straight edge and compass to duplicate and bisect segments and angles, construct perpendiculars, parallel lines, figures, and circles with points of concurrency. Ample practice with 65 questions across 8 worksheets. No...
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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...
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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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Lesson Plan
Curated OER

Studying Special Segments in Triangles

For Teachers 8th - 10th
Learners 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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Assessment
Concord Consortium

In Oz We Tryst

For Students 9th - 11th Standards
The shortest distance from point A to point B is a straight line, but measuring distance gets more complicated when there are three points! Given the location of three friends, individuals determine the best point for all three friends...
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Lesson Plan
Curated OER

Cabri Jr. Perpendicular Bisector of a Chord

For Teachers 9th - 12th Standards
Your learners will construct the perpendicular bisector of a chord. They use Cabri Jr. to construct a circle and a perpendicular bisector of a chord. They then measure lengths of the chords and perpendicular bisectors. Learners use...
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Worksheet
Curated OER

Standardized Geometry Test Practice

For Students 10th
In this angles, lines and figures review worksheet, 10th graders solve and complete 33 standardized multiple choice problems. First, they use the Segment Addition Postulate to solve for a variable given an equation for each line. Then,...
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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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Lesson Plan
EngageNY

Characterize Points on a Perpendicular Bisector

For Students 9th - 10th Standards
Learn transformations through constructions! Pupils use perpendicular bisectors to understand the movement of a reflection and rotation. They discover that the perpendicular bisector(s) determine the line of reflection and the center of...
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Lesson Plan
EngageNY

Circles, Chords, Diameters, and Their Relationships

For Teachers 9th - 10th Standards
A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...
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Worksheet
Geometry Accelerated

Accelerated Geometry Review Sheet

For Students 8th - 10th Standards
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
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Lesson Plan
Curated OER

Bisecting Angles and Segments

For Teachers 9th - 12th
Learners bisect angles and segments using a mira. They measure the original angles and segments and the angles and segments formed by bisecting to better see the relationship between them.
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Lesson Plan
Curated OER

Isosceles Triangles

For Teachers 9th - 10th
Students identify the properties of an isosceles triangle. In this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
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Lesson Plan
EngageNY

Designing a Search Robot to Find a Beacon

For Students 9th - 12th Standards
Build right angles using coordinate geometry! Pupils explore the concept of slope related to perpendicular lines by examining 90-degree rotations of right triangles. Learners determine the slope of the hypotenuse becomes the opposite...
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Unit Plan
Curated OER

Connecting Algebra and Geometry Through Coordinates

For Teachers 9th - 10th Standards
This unit on connecting algebra and geometry covers a number of topics including worksheets on the distance formula, finding the perimeter and area of polynomials, the slope formula, parallel and perpendicular lines, parallelograms,...
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Lesson Plan
Curated OER

Exploring Special Segments in Triangles

For Teachers 9th - 12th
Young scholars discover that four special segments have a common intersection point. They identify the position of the intersection point in triangles. They produce conjectures about areas of the divided triangles.
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Lesson Plan
Curated OER

Constructing Perpendiculars

For Teachers 9th - 10th
Learners construct perpendicular lines. In this geometry lesson, students use a compass and straight edge to do construction. They start from a point to a line.