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Lesson Plan
Curated OER

Angle Bisectors and Medians of Quadrilaterals

For Teachers 9th - 12th Standards
Young scholars investigate the properties of quadrilaterals formed by angle bisectors of a given quadrilateral and quadrilaterals formed by the medians of quadrilaterals. This Cabri Jr. lesson provides opportunity for conjecture and...
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Lesson Plan
Curated OER

Altitude, Median, and Angle Bisector of a Triangle

For Teachers 9th - 12th Standards
Learners investigate the special properties of an altitude, a median, and an angle bisector and explore how these special segments divide the area of a triangle. The dynamic nature of Cabri Jr. allows pupils to form and verify conjectures.
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Interactive
CK-12 Foundation

Bisectors of Line Segments and Angles: Cut an Angle

For Students 6th - 10th
Explore constructions through an interactive online lesson. Given an example of an angle bisector construction, learners investigate the markings to determine the method used. Challenge questions help solidify the steps. 
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Lesson Plan
Curated OER

Investigating a Point on an ANgles Bisector

For Teachers 7th - 9th
Students investigate points and angle bisectors. In this geometry lesson, students define angles, bisectors and perpendicular bisectors. They analyze angles and bisectors using Cabri software.
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Interactive
CK-12 Foundation

Bisectors of Line Segments and Angles: Cut a Line

For Students 9th - 12th
Geometric constructions build relationships —by simply manipulating simple tools. An interactive lesson presents a completed construction of a segment bisector and has learners analyze the important aspects. Ultimately, they should be...
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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 plan, 10th graders construct perpendicular lines and discuss midpoint, segments and perpendicular bisectors. They relate...
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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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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
Curated OER

Constructing Perpendiculars

For Teachers 9th - 10th
Young scholars 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.
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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
Bowland

Pointzero: Confined

For Teachers 6th - 8th Standards
Groups plan their escape carefully. Three three-tiered puzzles help a story character escape their situation, each involving integer sequences, transformations, and geometric constructions. The teacher resource includes slides and...
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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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Lesson Plan
Curated OER

Pedal Triangles

For Teachers 8th - 10th
Students identify the properties and theorems of triangles. In this geometry lesson plan, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
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Lesson Plan
Curated OER

Special Triangles and Circles

For Teachers 9th - 11th
Students investigate special triangles and circles. In this geometry instructional activity, students construct a perpendicular bisector and discuss angles of a triangle. They find the angle bisectors, vetex and the types of circle...
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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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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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Lesson Plan
Curated OER

Incenter of a Triangle

For Teachers 10th
Tenth graders find the incenter of a triangle. In this geometry instructional activity, 10th graders define the way to create an incenter with an angle bisector. They differentiate between incenter and incircle.
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Lesson Plan
Curated OER

Heron's Formula

For Teachers 9th - 10th
Students use Heron's formula to calculate the area of a triangle. In this geometry lesson, students use three different methods to solve the area of a triangle. They find and construct the incentor and angle bisector of a triangle.
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Lesson Plan
Curated OER

Incenter of a Triangle

For Teachers 10th
Tenth graders explore the properties of the incenter of a triangle. For this geometry lesson, 10th graders construct a triangle and the angle bisectors of each angle. The dynamic properties of Cabri Jr. allow students to locate and...
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Lesson Plan
Curated OER

Contructions and Conjectures

For Teachers 10th - 11th
Students make constructions and conjectures. In this geometry lesson, students construct right, acute and obtuse angles using a straight edge and a protractor. They investigate parallel lines and the angles formed by the angles.
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Lesson Plan
Curated OER

The Search for Pythagoras' Treasure

For Teachers 8th - 10th
Students identify and define properties of triangles. In this geometry lesson plan, students identify the missing sides and angles of right triangles. They use the rules of the Pythagorean Theorem to solve their problems.
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Lesson Plan
Curated OER

Concurrent Lines in Triangles

For Teachers 9th - 12th
Students explore the concept of concurrent lines in triangles. In this concurrent lines in triangles lesson, students work in groups to investigate properties of concurrent lines in acute, right, and obtuse triangles. Students use a...
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Lesson Plan
Curated OER

Triangles with Collinear Circumcenters

For Teachers 9th - 10th
Students identify the circumcenter of a triangle. In this geometry lesson, students construct a perpendicular bisector using a straight edge and a compass. They differentiate between triangles and collinear points.
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Lesson Plan
Curated OER

Exploring Geometric Mean

For Teachers 8th - 10th
Students solve problems using geometric means. In this geometry lesson, students create altitudes in right triangles. They use Cabri software to move the triangle around and observe different sides and angles.