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Unit Plan
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EngageNY

Congruence, Proof, and Constructions

For Teachers 8th - 10th Standards
This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs.  Each of the almost-forty lessons is broken...
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Activity
National Council of Teachers of Mathematics

Taking a Spin

For Teachers 9th - 12th Standards
It does not divide into 360 evenly, so it cannot work. The resource extends pupils' thinking about rotational symmetry. By asking for a figure with a rotational symmetry of a seemingly impossible angle, the activity requires learners to...
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Interactive
Shodor Education Foundation

Transmographer

For Students 8th - 12th Standards
Introducing ... the Transmographer. Young mathematicians investigate translations, reflections, and rotations. The applet lets users perform transformations on triangles, squares, and parallelograms.
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Interactive
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GeoGebra

Leaping Lizards

For Students 9th - 12th Standards
Transform lizards onto different locations. The interactive provides a diagram of a lizard and several locations. Pupils use their knowledge of transformations to move the lizard to the different locations and use the tools of GeoGebra...
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Unit Plan
Mathematics Vision Project

Transformations and Symmetry

For Teachers 9th - 10th Standards
Flip, turn, and slide about the coordinate plane. Pupils define the rigid motions and experiment with them before determining the relationships of the slopes of parallel and perpendicular lines. The sixth unit in a nine-part series...
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Activity
Noyce Foundation

Between the Lines

For Students K - 12th Standards
Explore linear and square dimensions by comparing areas of similar figures. A creative set of five activities designed for elementary through high school classes asks young scholars to compare areas of specific polygons. The first two...
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Activity
Noyce Foundation

Once Upon a Time

For Students K - 12th Standards
Examine the relationship between time and geometry. A series of five lessons provides a grade-appropriate problem from elementary through high school. Each problem asks learners to compare the movement of the hands on a clock to an angle...
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Activity
Noyce Foundation

The Shape of Things

For Students K - 12th Standards
Investigate the attributes of polygons. A thorough set of lessons presents problem scenarios for elementary through high school classes. The first lessons focus on basic characteristics of polygons, including the line of symmetry. As the...
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Assessment15:11
Mathed Up!

Translations

For Students 9th - 12th Standards
Introduce translations as transformations that move figures in horizontal and vertical distances with a video that shows how to translate the figures. A second video covers how to determine the translation that has occurred. Pupils work...
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Assessment9:05
Mathed Up!

Enlargements

For Students 8th - 11th Standards
Make enlargements with and without centers. Pupils work through seven problems dealing with dilations or enlargements. The first couple items are strict enlargements without centers, while the others have centers. Class members also...
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Lesson Plan
California Mathematics Project

Reflections

For Students 8th - 10th Standards
Reflections are the geometric mirror. Pupils explore this concept as they discover the properties of reflections. They focus on the coordinates of the reflections and look for patterns. This is the third lesson in a seven-part series.
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Lesson Plan
EngageNY

End-of-Module Assessment Task - Geometry (module 1)

For Students 9th - 10th Standards
Have you hit a wall when trying to create performance task questions? Several open-ended response questions require a deep level of thinking. Topics include triangle congruence, quadrilaterals, special segments, constructions, and...
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Lesson Plan
EngageNY

Review of the Assumptions (part 2)

For Students 9th - 10th Standards
Is the amount of information getting overwhelming for your geometry classes? Use this strategy as a way to organize information. The resource provides a handout of information studied in relation to triangle congruence. It includes a...
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Lesson Plan
EngageNY

Translations

For Students 9th - 10th Standards
Learn through constructions! Learners examine a translation using constructions and define the translation using a vector. Pupils then construct parallel lines to determine the location of a translated image and use the vector as a guide.
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Lesson Plan
EngageNY

Review of the Assumptions (part 1)

For Students 9th - 10th Standards
What was the property again? Tired of hearing this from your pupils? Use this table to organize properties studied and as a reference tool for individuals. Learners apply each property in the third column of the table to ensure their...
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Lesson Plan
EngageNY

Mid-Module Assessment Task - Geometry (Module 1)

For Teachers 9th - 10th Standards
How do you prepare class members for the analytical thinking they will need in the real world? An assessment requires the higher order thinking they need to be successful. The module focuses on the concept of rigid transformations...
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Lesson Plan
EngageNY

Correspondence and Transformations

For Teachers 9th - 10th Standards
Looking for a strategy to organize the information related to transformations? The materials ask pupils to identify a sequence of rigid transformations, identify corresponding angles and sides, and write a congruence statement. They...
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Lesson Plan
EngageNY

Applications of Congruence in Terms of Rigid Motions

For Students 9th - 10th Standards
Corresponding parts, congruent parts, congruent corresponding parts—what does it all mean? The resource challenges pupils to identify corresponding parts for pairs of figures. It uses examples of figures that undergo rigid...
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Lesson Plan
EngageNY

Construct and Apply a Sequence of Rigid Motions

For Teachers 9th - 12th Standards
Breaking the rules is one thing, proving it is another! Learners expand on their previous understanding of congruence and apply a mathematical definition to transformations. They perform and identify a sequence of transformations and use...
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Lesson Plan
EngageNY

Looking More Carefully at Parallel Lines

For Students 9th - 10th Standards
Can you prove it? Making assumptions in geometry is commonplace. This resource requires mathematicians to prove the parallel line postulate through constructions. Learners construct parallel lines with a 180-degree rotation and then...
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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

Rotations, Reflections, and Symmetry

For Teachers 9th - 10th Standards
Lead your high school class on a journey through the world of symmetry and reflections as you discuss geometric principles. Pupils differentiate between reflections and rotations, explore rotational symmetry, and investigate how to...
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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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Lesson Plan
EngageNY

Rotations

For Teachers 9th - 10th Standards
Searching for a detailed lesson to assist in describing rotations while keeping the class attentive? Individuals manipulate rotations in this application-based lesson depending on each parameter. They construct models depending on the...