Sonoma State University
Sonoma State University: Parallel Lines and Similar and Congruent Triangles
This site defines eleven theorems relating to parallel lines and similar and congruent triangles. Links to the theorems and relevant term descriptions are provided.
Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Geometry Distance of Triangles Using a Protractor
Basic exercises are presented to help students understand the concept of the area of triangles and the angles of a triangle.
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...
Mangahigh
Mangahigh: Shape: Recognize Congruent Shapes
Determine whether shapes are congruent or similar.
Texas Education Agency
Texas Gateway: Writing Geometric Relationships
Given information in a geometric context, students will be able to use informal arguments to establish facts about the angle sum and exterior angle of triangles, the angles created when parallel lines are cut by a transversal, and the...
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 instructional activity incorporates history, math, and language arts. In this instructional...
Hunkins Experiments
Hunkin's Experiments:how to Measure the Height of a Tree
Hunkin's Experiments is a group of simple cartoon illustrations of scientific principles. Some would work well in the classroom, but others have little value beyond entertaining students. All of the projects are easy to do. This part...