Curated OER
Dilations in the Plane
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.
EngageNY
Properties of Dilations
Investigate dilations to learn more about them. The second segment in a series of 16 provides a discussion of properties of dilations by going through examples. The problem set provides opportunities for scholars to construct dilations.
Curated OER
Similarity and Dilations - Discover Properties of Similar Figures
Learners investigate properties of similar figures. In this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...
Curated OER
Dilations with Matrices
Math whizzes explore dilations. They use matrices to perform dilations centered at the origins of triangles and investigate the effect of scale factor on the size relationship between the pre-image and the image of a polygon. A link to...
University of Utah
Geometry: Transformations, Congruence, and Similarity
Rigid motions are to congruence as what are to similarity? Investigate properties of rigid motions and define congruence in terms of rigid motions with the ninth chapter of a 10-part eighth grade workbook series. The lesson then prompts...
Curated OER
Investigate the Rigid Motions of Reflection, Rotation, Translation, and Dilation
Students investigate the rigid motions of reflection, rotation, translation, and dilation. This investigation be accomplished through classroom instruction and exploration using Geometer's Sketchpad.
Mathematics Assessment Project
Evaluating Statements About Enlargements
Double, toil ,and double linear dimensions. Learners first complete an assessment investigating how doubling linear dimensions affects the area of pizzas and the volume of popcorn containers. They then complete an activity investigating...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Mathed Up!
Negative Scale Factor
Class members investigate the effect of a negative scale factor dilation on coordinate shapes as they watch a short video that shows an example of a geometric figure undergoing a dilation with a negative scale factor. Learners then try a...
PBS
Human Tree: Ratios
Create a personal tree. By visiting an exhibit at the National Museum of Mathematics, the resource introduces the idea of fractals. The exhibit takes an image of the person and creates a tree by repeating scaled images on the shoulders...
Virginia Department of Education
Quadratic Modeling
Use a one-stop resource for everything you'd possibly want to teach about quadratic functions and models. Scholars analyze key features of quadratic functions as well as transformations of functions through seven activities....
Curated OER
Dilations- What a Stretch!
High schoolers perform dilation on various geometric shapes. They also discuss pros and cons of dilation and employ the Frayer Model to study the vocabulary words in this section.
EngageNY
Transformations of the Graphs of Logarithmic and Exponential Functions
Transform your activity on transformations. Scholars investigate transformations, with particular emphasis on translations and dilations of the graphs of logarithmic and exponential functions. As part of this investigation, they examine...
Curated OER
Reflections over Two Lines & Dilations
Students create reflections over two lines. In this reflections worksheet, students compare and contrast reflections over parallel and intersecting lines. They dilate figures and investigate the effect of the dilation using measurement...
EngageNY
The Scaling Principle for Area
As they investigate scaling figures and calculate the resulting areas, groups determine the area of similar figures. They continue to investigate the results when the vertical and horizontal scales are not equal.
EngageNY
General Pyramids and Cones and Their Cross-Sections
Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...
EngageNY
Coordinates of Points in Space
Combine vectors and matrices to describe transformations in space. Class members create visual representations of the addition of ordered pairs to discover the resulting parallelogram. They also examine the graphical representation of...
Bowland
Design the Mascot
Explore how resizing an object affects its area. The set of lessons challenges young mathematicians to design a mascot for electronic devices. These designs undergo resizing to determine how scale factors of dilation affect area.
Virginia Department of Education
Similar Triangles
Pupils work in pairs to investigate what it takes to prove that two triangles are similar. They work through various shortcuts to find which are enough to show a similarity relationship between the triangles. Small groups work with the...
Curated OER
Dilations of 2 and 3 dimentional figures and their effect on area, surface area, and volume.
Seventh graders investigate the area and volume of 2D and 3D figures. In this geometry instructional activity, 7th graders create a storyboard explaining their knowledge of 2D and 3D shapes. They analyze their data and interpret their...
Curated OER
Twists and Turns
Pupils reflect, rotate, translate, and dilate figures in the Cartesian coordinate plane using grid paper and dot paper. They use transformations (i.e., reflections, translations, rotations, and dilations) to describe geometric patterns...
Texas Instraments
Angles in Circles
Teach your learners how to investigate the relationship between a central angle and an inscribed angle which subtend the same arc of a circle. The dynamic nature of Cabri Jr. provides opportunity for conjecture and verification.
Curated OER
Scale Factor Area Perimeter
Mathematicians compare triangles at different scales. In this geometry lesson, students calculate the area and perimeter of triangles. They use the Ti to make observation of the change that takes place as the triangles are dilated.
EngageNY
Basic Properties of Similarity
Does the symmetry and transitive property apply to similarity? The 10th segment in a series of 16 presents the class with a group of explorations. The explorations have pairs show that similarity is both symmetrical and transitive. It...