Corbett Maths
Enlargements with Negative Scale Factor
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...
Corbett Maths
Enlargements with Fractional Scale Factors
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...
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...
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...
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
Examples of Dilations
Does it matter how many points to dilate? The resource presents problems of dilating curved figures. Class members find out that not only do they need to dilate several points but the points need to be distributed about the entire curve...
Curated OER
Dilations and Similarity
In this dilations and similarity instructional activity, pupils solve 10 different problems that include various dilations. First, they determine the scale factor of dilations found in the illustrated graphs. Then, everyone determines...
Charleston School District
Constructing Dilations
Pupils multiply the vertical and horizontal distances from the center of dilation by the scale factor. The independent practice prompts the class to analyze the relationship between the image and pre-image. The lesson is part three in a...
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
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
Dilations on the Coordinate Plane
Dilations from the origin have a multiplicative effect on the coordinates of a point. Pupils use the method of finding the image of a point on a ray after a dilation to find a short cut. Classmates determine the short cut of being able...
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...
Curated OER
Dilations with Matrices
Examine dilation with matrices with your class. Learners write a conjecture for how the scale factor determines the size of an image. They then use their conjecture to write a matrix multiplication problem for the illustrated triangle...
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.
Corbett Maths
Describing Enlargements
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.
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
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...
Curated OER
Geometry Worksheet 9.5: Rotational Symmetry
In this rotational symmetry worksheet, high schoolers solve 14 short answer and graphing problems. Students identify the order and magnitude of given figures. High schoolers find the scale factor of a dilation given a graph.
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.
Mathed Up!
Enlargements
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...
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
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...
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...