Journey Through the Universe
The Voyage Scale Model Solar System
Young scientists learn how to select a scale factor for a large scale model. Then they figure the scale for each of the planets and the distance between them. Finally, they construct a giant scale model of the solar system and answer...
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.
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...
GeoGebra
Triangle Dilations
Stretch the class' knowledge of dilations. With the aid of the rubber band stretcher tool, learners perform dilations. They dilate the triangle by a whole number scale and a fractional scale from two centers of dilation.
Mathematics Assessment Project
Solving Problems with Circles and Triangles
After completing a task involving examining the ratio of areas of triangles and circles in a given figure, scholars examine sample responses to identify other strategies they could use to solve the problem.
Journey Through the Universe
A Scale Model Solar System
Between the time scientists discovered Pluto and reclassified it as a dwarf planet, it did not even make one full revolution around the sun. In two activities, scholars investigate scale models and their properties. Pupils find that it...
Georgia Department of Education
Analytic Geometry Study Guide
Are you looking for a comprehensive review that addresses the Common Core standards for geometry? This is it! Instruction and practice problems built specifically for standards are included. The material includes geometry topics from...
Pearson
Performance Based Assessment Practice Test (Geometry)
The incredibly broad topic base of a geometry class makes full-length practice tests like this one, especially ones that include a number of open response questions, invaluable. Here the class can really get that hands-on experience...
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
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
Nested Similar Triangles
Nested triangles have been created so that they share a common vertex and vertex angle. Learners drag the endpoints of the side that is opposite the common angle to discover the conditions that make the nested triangles similar. When...
Curated OER
Angles and Similarity
Students identify triangles as similar or congruent. In this geometry instructional activity, students drag triangles around on the navigator to see the effect of different angles on the shape of the triangle. They discuss angle...
Curated OER
Corresponding Parts of Similar Triangles
Here is a lesson that has learners take a look at corresponding parts of similar triangles, ratios of similarity, reductions and enlargements. They'll manipulate the scale factor (r) to observe the changes in similar triangles and then...