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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
Curated OER

Bisectors of Triangles

For Teachers 10th
In this geometry worksheet, 10th graders solve problems involving the perpendicular bisectors and angle bisectors of a triangle and their points of concurrency.  The one page worksheet contains sixteen questions.  Answers are included. 
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Worksheet
Curated OER

Congruent Triangles

For Students 10th
In this congruent triangles worksheet, 10th graders solve and complete 16 different types of problems. First, they name the corresponding parts of the congruent triangles shown and draw a picture. Then, students list the five ways to...
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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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Assessment
Mathed Up!

Loci and Constructions

For Students 8th - 11th Standards
A General Certificate of Secondary Education math review has class members make basic constructions. Using a protractor and a ruler along with a compass, pupils develop drawings of triangles with given measurements. Scholars use their...
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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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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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Worksheet
Curated OER

Congruent Triangles

For Students 10th
In this congruent triangles worksheet, 10th graders solve and complete 13 different problems. First, they use the illustrated congruent triangles to show other congruency in each problem. Then, students determine and prove the angle...
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Lesson Plan
Curated OER

Incenter of a Triangle

For Teachers 10th
Tenth graders find the incenter of a triangle. For this geometry lesson, 10th graders define the way to create an incenter with an angle bisector. They differentiate between incenter and incircle.
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Unit Plan
Mathematics Vision Project

Module 3: Geometric Figures

For Teachers 9th - 12th Standards
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
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Unit Plan
Curated OER

Transformations in the Coordinate Plane

For Teachers 9th - 12th Standards
Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...
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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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Assessment
Concord Consortium

Detective Stories

For Students 9th - 12th Standards
The truth will always come out. A short performance task has learners considering a witness statement given to a detective. They apply special line segments in triangles and Ceva's Theorem to prove that the witness is actually lying.
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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

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

Geometry Standardized Test Practice

For Students 10th
In this angles and figures review worksheet, 10th graders solve and complete 39 different multiple choice problems. First, they find the length of a line between two given points. Then, students name the type of transformation and the...
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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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Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve and complete 6 various types of problems. First, they draw a median and the altitude from the given angle in each triangle illustrated. Then, students determine which angle is equidistant...
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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

Ruler and Compass Constructions

For Teachers 4th - 5th
Fourth and fifth graders examine how to construct perpendicular lines and to bisect angles using rulers and compasses in this unit of lessons. They design a number of polygons using these methods.
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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

Constructions of Isosceles and Equilateral Triangles

For Teachers 4th - 9th
Students explore the difference between drawing and constructing a triangle utilizing The Geometer's Sketchpad on the computer. They create, develop and script constructions for both isosceles and equilateral triangles. Each student has...
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Lesson Plan
Curated OER

Exploring Centers of Triangles

For Teachers 7th - 10th
Students explore properties of triangles using angle bisectors, incenters, circles, midpoints, and altitudes. They use Geometer's Sketchpad in order to create triangles and their properties.
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Lesson Plan
Curated OER

Hospital Locator

For Teachers 7th - 9th
Pupils apply properties of triangles to the real world. In this geometry lesson, students identify the median and angle bisectors of triangles. They plan the appropriate are to place a new medical center based on their knowledge of...