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
Making Scale Drawings Using the Ratio Method
Is that drawn to scale? Capture the artistry of geometry using the ratio method to create dilations. Mathematicians use a center and ratio to create a scaled drawing. They then use a ruler and protractor to verify measurements.
EngageNY
Scale Drawings
Are you searching for a purpose for geometric constructions? Use an engaging approach to explore dilations. Scholars create dilations using a construction method of their choice. As they build their constructed dilation, they strengthen...
EngageNY
How Do Dilations Map Segments?
Do you view proofs as an essential geometric skill? The resource builds on an understanding of dilations by proving the Dilation Theorem of Segments. Pupils learn to question and verify rather than make assumptions.
EngageNY
Dilations from Different Centers
Can you follow a composition of transformations, or better yet construct them? Young mathematicians analyze the composition of dilations, examining both the scale factor and centers of dilations. They discover relationships for both and...
EngageNY
How Do Dilations Map Lines, Rays, and Circles?
Applying a learned technique to a new type of problem is an important skill in mathematics. The lesson asks scholars to apply their understanding to analyze dilations of different figures. They make conjectures and conclusions to...
West Contra Costa Unified School District
Dilations Using Right Triangles
Don't argue with a triangle that has a 90-degree angle. It's always right. Scholars first use right triangles to help draw dilations of points. They continue the instructional activity by applying this skill to draw dilations of polygons.
Illustrative Mathematics
Dilating a Line
High School geometers verify through experimentation certain properties about dilations. This multi-step problem challenges them to construct examples of dilations to verify specific facts, the final step provides an opportunity to more...
EngageNY
Making Scale Drawings Using the Parallel Method
How many ways can you create a dilation? Many! Individuals strengthen their understanding of dilations by using various methods to create them. The new technique builds on pupils' understanding of the ratio method. Using the ratio,...
EngageNY
Informal Proofs of Properties of Dilations
Challenge the class to prove that the dilation properties always hold. The lesson develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member performing the...
EngageNY
What Lies Behind “Same Shape”?
Develop a more precise definition of similar. The lesson begins with an informal definition of similar figures and develops the need to be more precise. The class learns about dilations and uses that knowledge to arrive at a mathematical...
EngageNY
Comparing the Ratio Method with the Parallel Method
Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...
Curated OER
Dilations
In this dilations worksheet, students draw and label dilated images for the triangles and label the centers. Students complete 6 problems total.
EngageNY
Dilations as Transformations of the Plane
Compare and contrast the four types of transformations through constructions! Individuals are expected to construct the each of the different transformations. Although meant for a review, these examples are excellent for initial...
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...
EngageNY
Scale Factors
Is it bigger, or is it smaller—or maybe it's the same size? Individuals learn to describe enlargements and reductions and quantify the result. Lesson five in the series connects the creation of a dilated image to the result. Pupils...
EngageNY
Complex Numbers and Transformations
Your learners combine their knowledge of real and imaginary numbers and matrices in an activity containing thirty lessons, two assessments (mid-module and end module), and their corresponding rubrics. Centered on complex numbers and...
EngageNY
Mid-Module Assessment Task - Geometry (Module 2)
Challenge: create an assessment that features higher level thinking from beginning to end. A ready-made test assesses knowledge of dilations using performance tasks. Every question requires a developed written response.
GeoGebra
Photocopy Faux Pas
Why did it not copy correctly? Using the tools in GeoGebra, pupils explore an image and its preimage. The learners determine what happened with the copying process and determine where they should position the preimage to obtain a...
Bowland
Three of a Kind
One is chance, two is a coincidence, three's a pattern. Scholars must determine similarities and differences of a regular hexagon undergoing dilation. They look at lengths, angles, areas, and symmetry.
Curated OER
Dilation
Tenth graders identidy and define various geometry terms, Students create exact replicas of a shape that is either smaller or larger than the original shape. Students prove that their entire shapes are larger or smaller in the same...
Corbett Maths
Enlargements Using Ray Method
Figure out what to do when there is no grid to count. Using a ruler and a sharp pencil, the narrator shows how to perform a dilation when the figure is not on a grid. The ray method works by drawing a ray from the center of dilation...
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...
Curated OER
Three Dimensional Sketching
Students become familiar with drawing segments and points. They understand how perspective drawing differs from three dimensional sketching. They demonstrate three dimensional and perspective drawing.