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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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Worksheet
Curated OER

List of Geometry Terms

For Students 4th - 9th
In this angle vocabulary card instructional activity set, students identify the vocabulary associated with angles such as: ray, vertex, acute angle, segment bisector, and corresponding angles. They identify 23 terms but there are no...
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Lesson Plan
EngageNY

Reflections

For Teachers 9th - 10th Standards
Facilitate creativity in your math class as individuals learn the definition of a geometric reflection and correctly construct a model, as well as its reflected image. They use a perpendicular bisector and circles to elaborate on...
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Worksheet
Curated OER

Concurrent Lines, Medians and Altitudes

For Students 9th - 10th
In this geometry instructional activity, students construct angles and identify medians and altitudes. They use a compass and protractor to perform heir construction. There are 28 questions.
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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

Geometric Construction

For Teachers 7th
Seventh graders investigate some concepts associated with geometric shapes. They study the bisector segment and the perpendicular line to a given line. Students conduct analysis with the goal of deepening observation and deduction...
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Worksheet
Curated OER

Triangle Fundamentals Homework

For Students 9th - 10th
In this geometry worksheet, students identify the missing angles of non right triangles using the angle sum theorem. They solve for the unknown using algebra. There are 21 questions.
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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.
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Lesson Plan
Curated OER

Exploring Geometric Mean

For Teachers 8th - 10th
Student identify the solution using geometric mean. In this geometry instructional activity, students create right triangles where the altitude of the triangle is the side containing the right angle. They modify shapes using Cabri...
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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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Lesson Plan
Curated OER

Investigating Trigonometric Ratios Through Similar Right Triangles

For Teachers 9th - 10th
Students identify similar and congruent right triangles. For this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.
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Handout
Lockport City School District

Reasons for Geometric Statement/Reason Proofs

For Students 8th - 11th Standards
Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs. 
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Lesson Plan
EngageNY

Triangle Congruency Proofs (part 1)

For Teachers 9th - 10th Standards
Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...
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Unit Plan
Mathematics Vision Project

Module 6: Congruence, Construction, and Proof

For Teachers 8th - 10th Standards
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This unit...
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App
Bytes Arithmetic

Geometry Pad+

For Students 6th - 10th Standards
Graphing paper, pencil, ruler, protractor, and compass, all get replaced or supplemented with this dynamic geometry application. Here, you can create, move, and scale many different shapes, as well as, explore and change their properties...
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Lesson Plan
Curated OER

Exploring Centers of a Triangle: Part 1

For Teachers 9th - 11th
Students use problem solving skills, formal geometry, and The Geometer?s Sketchpad. They model and solve two real-world problems by constructing the in center and circumcenter of triangles.
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Lesson Plan
Curated OER

Properties of Special Parallelograms

For Teachers 8th - 10th
Students identify properties of parallelograms. In this geometry lesson, students label polygons as parallelogram or not. They define and label the properties of a kite.
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Worksheet
Curated OER

The Relationship Between Slope and Perpendicular Lines

For Students 8th - 9th
In this perpendicular lines activity, students explore the relationship between perpendicular lines and slope in eight exercises and two worked examples.  The solutions are provided.
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Lesson Plan
Curated OER

Constructions of Isosceles and Equilateral Triangles

For Teachers 4th - 9th
Pupils 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 to...
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Lesson Plan
Curated OER

Plenty of Pythagoras

For Teachers 5th - 8th
Using a twelve foot knotted rope, students form a 3-4-5 right triangle. Following a discussion of observations about the lengths of the sides of the triangle, students use grid paper, scissors and a centimeter ruler to draw and measure...
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Lesson Plan
Curated OER

Finding the Area of Triangles

For Teachers 12th
Twelfth graders apply the formula for finding the area of a triangle to various problems. They work real life problems for finding the area of a bathroom and the cost of tiling it. They play a game, Triangle Bingo, where they match...