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...

Rotations, reflections, and translations are explored as geometers rotate through three different stations and develop their own definitions for these terms. Afterward, they work in small groups to classify different figures based on...

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...

Introducing ... the Transmographer. Young mathematicians investigate translations, reflections, and rotations. The applet lets users perform transformations on triangles, squares, and parallelograms.

What do midpoints and perpendicular bisectors have to do with reflections? Learners first reflect line segments over the x- and y-axes. Using the results, they see how the line of reflection is a perpendicular bisector for segments...

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...

Begin with a performance and end with a definition. Learners rotate a point about another point, documenting the steps. The scholars use their steps to create a definition of a rotation that is general enough to use for any degree of...

Develop a definition based upon the performance. Using a line and a point, pupils reflect the point across the line. The learners use the steps in creating the reflection to develop a precise definition of a reflection.

Translate from action to a definition. Given a point and a directed line segment, learners conduct a transformation. The scholars record the steps they take while performing the transformation. The individuals develop a definition from...

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...

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...

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...

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...

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...

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...

Have classes been going in circles as they study rotations! Math scholars begin with an exploration of rotations using patty paper. As they progress through the lesson, they examine compositions of reflections and their resulting image....

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.

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...

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...

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.

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...

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...

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...