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
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.
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
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...
Curated OER
Coordinate Plane Transformations
Geometric transformations are explored by high schoolers. They will create a set of instructions for plotting coordinates representing an original transformation of a real-world figure. These instructions are shared with middle...
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
Time Dilation and Geometry
Young scholars solve problems of dilation and velocity. In this geometry instructional activity, students apply the Pythagorean Theorem to solve problems and relate it to time and velocity.
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
Investigate the Rigid Motions of Reflection, Rotation, Translation, and Dilation
Young scholars investigate the rigid motions of reflection, rotation, translation, and dilation. This investigation be accomplished through classroom instruction and exploration using Geometer's Sketchpad.
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...
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,...
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...
Illustrative Mathematics
Similar Triangles
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
Illustrative Mathematics
Similar Circles
Young geometers flex their transformation muscles in this brief but powerful exercise using dilations and translations to develop the similarity of circles. The plan provides guidelines to help learners navigate a pair of deceptively...
EngageNY
Dividing the King’s Foot into 12 Equal Pieces
Apply, apply, apply! A measurement lesson plan applies a number of concepts to help learn a new construction. Scholars learn to divide a segment into n equal parts using a method that uses the Side Splitter Theorem and a method that...
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
Geometric Transformations
Learners examine images and preimages of a mapping and identify isometry. They view images by M.C. Escher, observe teacher demonstrations, and create a translation image, a rotation image, and a dilation.
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...
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.
Mathematics Vision Project
Module 5: Circles A Geometric Perspective
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
Curated OER
Symmetry of Road Signs
Students identify symmetry in road signs. In this geometry lesson, students explore objects in the real world for symmetry. They perform translation, rotation and reflection.
Curated OER
Reflections over Two Lines & Dilations
Young scholars 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...
Curated OER
Twists and Turns
Students 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...
Curated OER
Transformations on the Coordinate Plane
Here is a study guide on transformations that includes reflections, translations, dilations, and rotations. It also has definitions, helpful diagrams, and several examples involving transformations on the coordinate plane. The lesson...