ClassFlow
Class Flow: Classifying Triangles
[Free Registration/Login Required] This flipchart introduces students to the different types of triangles and how to classify them.
ClassFlow
Class Flow: Difference of Squares (Algebra)
[Free Registration/Login Required] Pythagorean triples described using a number of triangles. Pythagorean Theorem reinforced using squares and triangles. Assessment built in.
ClassFlow
Class Flow: Measure and Draw Angles
[Free Registration/Login Required] This lesson has many student interactive tricks. It is very exciting and gets the students actively engaged as they solve problems on the board. The lesson is an introduction to angles. It also reviews...
ClassFlow
Class Flow: Understanding Basic Triangles
[Free Registration/Login Required] This lesson presents an introduction to triangles and the methods of identifying them. It includes opportunities for students to interactively identify triangles. It also includes: assessment questions...
University of Cambridge
University of Cambridge: Nrich: Adding Triangles
Sharpen your logic and geometry skills by finding the area of a triangle. Solution available.
University of Cambridge
University of Cambridge: Nrich: Games the Triangle Game
Use this game to improve your knowledge and understanding of triangles and naming vertices. Just read and follow the instructions! [Requires Java.]
University of Cambridge
University of Cambridge: Nrich: Four Triangles Puzzle
Sharpen your logic and and pattern recognition skills with this four triangles puzzle. The solution is available to check your work.
University of Cambridge
University of Cambridge: Nrich: Sticky Triangles
On this one page website sharpen your logic, table making, and pattern recognition skills while working on this triangle challenge. The solution is available to double check your solution.
Other
Math4 Children: Shapes and Their Names Quiz
This 8 question quiz has children look at a shape and select the correct name for it. Links to other quizzes and games are provided. PDF Reader is required.
That Quiz
That Quiz: Triangulos
These interactive activities are designed to examine the mathematical concepts of length, perimeter, and area. These activities may be used to develop students' understanding of these mathematical concepts.
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.
National Council of Teachers of Mathematics
The Math Forum: Problems Library Geometry Triangles
This site contains a wealth of problems that deal with the basic definitions of medians, altitudes, angle bisectors, and perpendicular bisectors or the defining characteristics of the different types of triangles. There are also...
University of Cambridge
University of Cambridge: Nrich: Seven Sticks
On this one page website sharpen your logic, triangle properties, and pattern recognition skills while working on this challenge. The solution is available to double check your solution.
ClassFlow
Class Flow: Playing With Shapes
[Free Registration/Login Required] This flipchart is a small lesson for 2nd grade math-geometry. Once students have been introduced to the key vocabulary terms in geometry, the teacher can reinforce those shapes, terms, and some...
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Types of Triangles
Find a quick, concise explanation of the different types of triangles. Examples are given and clearly explained.
University of Georgia
University of Georgia: Inter Math: Incenter
This InterMath site gives a description of the incenter of a triangle along with a visual representation. Be sure to follow the links to related terms, everyday examples, challenging problems, and the interactive check point involving...
Other
Ministerio De Educacion: Triangulos
See if you can find all the triangles following a certain order.
Purple Math
Purplemath: Proportions: Introduction
Explains the basics and terminology of proportions.
Purple Math
Purplemath: Geometry Word Problems: Introduction
Introduces how to set up and solve simple geometric-figure word problems. Includes advice regarding formulas to memorize.
Other
Lifewire: Excel Tan Function: How to Find the Tangent Angle
This article shows you how to find the tangent angle using Excel. You may be able to accomplish this on a scientific calculator, but if you don't have one handy, Excel can help you make these calculations better than anything else.
SMART Technologies
Smart: Polygons
This SMART Notebook lesson allows students to characteristics of polygons by exploring vocabulary and sample problems.
Wolfram Research
Wolfram Math World: Scalene Triangles
MathWorld gives a brief definition of scalene triangles and then lists links to related topics and terms.
Math Words
Math words.com: Altitude of a Triangle
This site provides a definition of what the altitude of a triangle is. It also provides a diagram.
Wikimedia
Wikipedia: Percussion
A basic article on percussion instruments lists several examples of percussion instruments, provides a distinction between membranophones and idiophones, and lists instruments that are tuned vs. ones that are not.