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.
Government of Alberta
Learn Alberta: Exploring Similarity and Congruence
Begin by watching this captivating video showing how the concepts of similarity and congruence are found in road signs. Following the video [1:27], an interactive applet allows students to resize, flip, move and rotate triangles to...
National Council of Teachers of Mathematics
The Math Forum: Similarity and Congruence
This site from Dr. Math at the Math Forum provides a collection of problems and exercises that require knowledge of the relations between similar or congruent shapes. Solutions are provided.
CK-12 Foundation
Ck 12: Geometry: Similar Polygons and Scale Factors
[Free Registration/Login may be required to access all resource tools.] Apply the properties of similar polygons.
CK-12 Foundation
Ck 12: Geometry: Perimeter and Area Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide looks at the definitions and units for perimeter, area, and circumference, and at the perimeter and area of different shapes, including regular...
Illustrative Mathematics
Illustrative Mathematics: G Srt, G Mg How Far Is the Horizon?
Some friends are at the beach looking out onto the ocean on a clear day and they wonder how far away the horizon is. A second problem asks how far the horizon would be from the top of a mountain. Students must also answer a question...
Illustrative Mathematics
Illustrative Mathematics: G Srt Joining Two Midpoints of Sides of a Triangle
In this task, students must prove that angles and triangles are congruent and that a parallel line passes through the midpoints of two sides of the larger triangle. Aligns with G-SRT.B.4.
The Math League
The Math League: Similar Figures
This tutorial explains what similar figures are in geometry and provides examples.
ClassFlow
Class Flow: Transformations
[Free Registration/Login Required] In this flipchart, students apply multiple transformations to create congruent and similar figures in any or all of the four quadrants. Students apply their geometric sense by using multiple...
Cuemath
Cuemath: Median of a Triangle
This lesson explores the equation of the median of a triangle formula, sum of medians of a triangle, altitude of a triangle, median of equilateral triangle formula, and median of a triangle definition while discovering the interesting...
Better Lesson
Better Lesson: Geometric Transformations
Search for common core lesson plans on geometric transformations.
National Council of Teachers of Mathematics
Nctm: Illuminations: Making Triangles
Understand the mathematical meaning of a triangle and the idea of congruence, or sameness, in geometry.
CK-12 Foundation
Ck 12: Interactive Middle School Math 8 for Ccss
A complete CCSS Grade 8 Mathematics course that includes interactives in every lesson, plus videos, hands-on activities, and questions with immediate feedback. Every lesson also has specifically chosen 'Related Modalities' that teach the...
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...
University of Saskatchewan (Canada)
University of Saskatchewan: Triangles
This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.
Mocomi & Anibrain Digital Technologies
Mocomi: Types of Triangles
Explore the different types of triangles and other properties.
Rice University
Rice University: Cynthia Lanius: Polyominoes Fun With Dominoes
For students who have ever played dominoes and Tetris, polyominoes will strike them as a great deal of fun. Teachers will see the educational benefits of working with similar and congruent shapes and rotating them in a plane. Exploration...
Alabama Learning Exchange
Alex: Tan Ii
The Chinese character mark for Tan II (pronounced she-tow-bah) is the second of two lessons to introduce first grade students to geometry using tangrams. This lesson incorporates history, math, and language arts. In this lesson students...
Alabama Learning Exchange
Alex: "Tan"
The Chinese character mark formerly known as "Tan" is the first of two lessons to introduce first grade students to geometry using tangrams. This lesson incorporates history, math, and language arts. In this lesson students will be able...
Other
Nearpod: Introduction to Geometric Transformations
In this lesson plan, students will learn how to describe and identify reflections, rotations, translations, and dilations.
ClassFlow
Class Flow: Angles in Geometry
[Free Registration/Login Required] This flipchart is a look at angles in geometry. Drawing, labeling, measuring, special angles: (right, straight, acute, obtuse) and congruence.