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...

Tenth graders investigate dilations and explore the dilation transformation before investigating the properties of a dilation using Cabri Jr. High schoolers extend the concept of dilatation to the coordinate plane.

New ReviewTry to keep the pipe short. Learners investigate where to place a water pump to use the least amount of pipe. Scholars use their knowledge of reflections and congruent triangles to find the best location for the water pump. Finally, they...

Where does the reflection come from? The vivdeo starts with a quick review of the form of the equation of horizontal and vertical lines and diagonals passing through the origin. Using a pre-image and an image of a reflected figure, the...

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...

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...

How will a scale factor affect a figure—negatively? Using a grid, the narrator of an engaging video performs a dilation with a negative scale factor. The presenter compares a positive scale factor with a negative scale factor to explain...

Enlargements make it bigger, right? A video shows viewers how to perform a basic dilation with a fractional scale factor. They learn how to use the scale factor to find the location of the transformed vertex by multiplying the horizontal...

Where did the transformation begin? Using a ruler, the narrator of a short presentation shows how to find the center of enlargement for transformed figures. Worksheets provide the class members an opportunity to practice the newly...

What caused that to happen? Using three aspects, a video demonstrates how to describe an enlargement or dilation. The presenter counts the lengths of the sides to determine the scale factor and a ruler to find the center of dilation.

Don't flip out over the resource, but be sure to flip the figures. By watching a short YouTube video, scholars learn about reflections in the coordinate plane. They see how to identify the line of reflection given two figures.

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...

Develop a prime example of sliding about the coordinate plane. Using figures on the coordinate plane, a segment of an extensive geometry playlist introduces the transformation of translations. The presentation uses coordinate notation to...

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

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...

Spin the quadrilateral about a point. Pupils trace a figure they can use to determine the image of a figure rotated about a point. They draw the resulting image and label its vertices.

Slide into translations. Given a vector, pupils translate a quadrilateral on a grid system. The scholars use a tracing to determine the image of a quadrilateral. They label the vertices to show the correspondence between the pre-image...

Reflect on assessments. The formative assessment presents a quadrilateral and a line on a grid. Pupils use patty paper or a transparency to draw the reflected image of the quadrilateral over the line. The scholars label the image to show...

Oh, a change is gonna come. Scholars identify how transformations change a figure. They make generalizations about how different types of transformations affect angle measures and side lengths.

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...

Geometry in life-sized dimensions! Using enlarged graph paper, pupils perform a series of transformations. By recording the initial and final placement of the images, they are able to analyze the patterns in the coordinates during a...

Get learners' minds rotating and reflecting while looking for symmetry. Pupils investigate figures to determine the number of lines of symmetry and if the figure has rotational symmetry. Classmates work together in groups to find out the...

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...