EngageNY
Congruence, Proof, and Constructions
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...
Curated OER
Analyzing Congruence Proofs
Looking at numerous examples of triangles, each with different properties, geometers develop their understanding of congruency. They use the notation of a counter-example to disprove certain conjectures and prove geometric theorems and...
Flipped Math
Unit 11 Review: Circles
Solve problems around a circle. Pupils watch a video that shows how to apply concepts about circles and related angles and segments to find solutions to word problems. Learners then review the different concepts from the unit in...
Flipped Math
Rotations
Turn the class around. Scholars define rotations of multiples of 90 degrees and create algebraic mappings for them. After an introduction to symmetry, pupils determine which letters of the alphabet have rotational and reflectional...
Flipped Math
Transformations
Transformations come in many forms. To start the informative resource, pupils first review the different types of transformations. Scholars work in more detail with translations by drawing the transformations and writing the algebraic...
Flipped Math
Reflections
Take some time to reflect on graphing. Learners count a point's distance from the line of reflection to create reflections of geometric figures. Given the rules for four basic lines of reflections, pupils determine the points to create...
Radford University
Google Earth Trip
A trip around the world sounds nice, but for now we'll just have to make do with Google Earth. Pupils use pictures of landmarks to apply geometry concepts. They determine whether each building has bilateral or rotational symmetry, search...
Corbett Maths
Transformations: Translations
Slide into vector transformations. Column vectors define the translation of figures by defining the number of units to move horizontally and vertically on the coordinate graph. Pupils develop an understanding of how to read the...
Corbett Maths
Rotations
Develop the basics of turns. A helpful video discusses the information required to perform a rotation. Afterward, the narrator shows pupils how to perform a rotation by using a piece of tracing paper to determine where the image will be...
CCSS Math Activities
Smarter Balanced Sample Items: High School Math – Claim 2
Problem solve across the content standards. The presentation slides provide 19 sample items from the Smarter Balanced high school assessment. Items illustrate Claim 2, problem solving, of the test and are drawn from all the high school...
101 Questions
Best Reflection
Which is the best reflection of them all? Given four diagrams, pupils determine which one shows the most accurate reflection of a quadrilateral. Two images provide the distances of each vertex from the line of reflection, as well as the...
101 Questions
Pool Bounce
Use geometry to improve your pool game! Learners analyze the front half of a pool shot to determine its resulting path. By measuring the angle of incidence, they are able to predict the path of the ball.
Shodor Education Foundation
Transmographer
Introducing ... the Transmographer. Young mathematicians investigate translations, reflections, and rotations. The applet lets users perform transformations on triangles, squares, and parallelograms.
Mathematics Vision Project
Transformations and Symmetry
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...
Mathematics Vision Project
Congruence, Construction and Proof
Learn about constructing figures, proofs, and transformations. The seventh unit in a course of nine makes the connections between geometric constructions, congruence, and proofs. Scholars learn to construct special quadrilaterals,...
Noyce Foundation
The Shape of Things
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...
Virginia Department of Education
Transformations
The coordinate plane is a popular place! Identify rotations, reflections, and dilations on the coordinate plane. Pupils work in small groups to match transformations of a figure with the description of the transformation. They perform...
Mathed Up!
Reflections
Tracing paper is not just for art anymore — pupils can use it to find reflected images, too! Two videos show how to reflect images using tracing paper and find the reflection between the pre-image and image. Learners perform reflections...
Mathed Up!
Rotation
Two videos show first how to perform a rotation, given the center, the angle, and the direction of rotations. Individuals then see how to find what the rotation is from one figure to another. Pupils practice doing both in seven problems...
Balanced Assessment
Bouncing Off the Walls
Apply geometry concepts to improve your pool game! Here scholars create the perfect bank shot using angles of incidence and refraction. They create three different options for the same shot.
West Contra Costa Unified School District
Congruence Through Transformations
Transform your lesson on transformations. Learners use given congruent triangles and tracing paper to determine the single transformation that carries one to the other. The concept is extended to combinations of transformations to...
California Mathematics Project
Reflections
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 plan in a seven-part series.
Willow Tree
Transformations
How does something go from here to there? Describe it with a transformation. Young mathematicians learn how to translate, reflect, rotate, and dilate an image.
EngageNY
End-of-Module Assessment Task - Geometry (module 1)
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...