Texas Education Agency
Texas Gateway: Generalizing Geometric Properties of Ratios in Similar Figures
Students will investigate patterns to make conjectures about geometric relationships and apply the definition of similarity, in terms of a dilation, to identify similar figures and their proportional sides and congruent corresponding...
CK-12 Foundation
Ck 12: Geometry: Congruent Figures
[Free Registration/Login may be required to access all resource tools.] In this tutorial, students recognize congruence and find unknown measures of angles. They can examine guided notes, review guided practice, watch instructional...
Texas Instruments
Texas Instruments: Copying an Angle
Explore relationships (including congruence and similarity) among classes of two- and three-dimensional geometric objects, make and test conjectures about them, and solve problems involving them.
Texas Instruments
Texas Instruments: Similar Figures Discovery Activity
Students can use Cabri Jr. to discover two properties of similar triangles: corresponding angles are congruent and corresponding sides are proportional.
National Council of Teachers of Mathematics
Nctm: Figure This: Math Challenges for Families
Students, teachers, and parents alike will enjoy this challenging math site. It contains a clever brain teaser section plus creative problems related to algebra, geometry, measurement, numbers, statistics, and probability. A Spanish...
Sophia Learning
Sophia: Similarity
This learning tutorial describes the characteristics of similar figures and how to use scale factor and proportions to determine missing side lengths. The lesson includes PowerPoint presentations and videos demonstrating how to solve...
Sophia Learning
Sophia: Corresponding Parts: Lesson 5
This lesson will define the phrase corresponding parts (e.g. angles, sides, etc.). It is 5 of 5 in the series titled "Corresponding Parts."