Unit Plan
CK-12 Foundation

Ck 12: Elem Math: Classifying All Types of Triangles by Lengths of Sides

For Students 3rd - 5th Standards
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying triangles based on length of sides.
Unknown Type
Math Open Reference

Math Open Reference: Triangle Quiz

For Students 6th - 8th Standards
Students are assessed on different types of triangles. Definitions of the triangles are included.
Handout
Merriam-Webster

Merriam Webster: Dictionary Illustration: Types of Triangles

For Students 3rd - 8th Standards
A labeled illustration of six different types of triangles.
Handout
Wolfram Research

Wolfram Math World: Equilateral Triangle

For Students 9th - 10th Standards
MathWorld goes into detail about equilateral triangles at this site. Use this site to find out how to construct an equilateral triangle using a compass and straight edge. Learn about the altitude of such triangles, and the rationality of...
Handout
Oswego City School District

Regents Exam Prep Center: Triangle Information

For Students 6th - 8th Standards
This Oswego City School District site from the Regents Exam Prep Center provides an explanation of the classifications of triangles both by sides and by angles. Pictures are also included.
Interactive
National Institute of Educational Technologies and Teacher Training (Spain)

Ministerio De Educacion: Veintiocho Cerillas

For Students 2nd - 8th Standards
Remove four matches to the center of the square then repositions the other matches in such a way that the sum of them on each side is 11.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Gpe, N Rn, F Tf Coordinates of Equilateral Triangles

For Teachers 9th - 10th
In this task, students are asked if there is an equilateral triangle ABC where two vertices are on the x-axis, and all vertices have integer coordinates. Aligns with G-GPE.B, N-RN.B, and F-TF.C.9.
Unit Plan
Math Open Reference

Math Open Reference: Triangles

For Students 9th - 10th Standards
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
Handout
Analyze Math

Analyze Math: Free Math Tutorials: Triangles

For Students 9th - 10th Standards
The geometry tutorial investigates the definitions and properties of triangles. Topics included are isosceles, equilateral, and right triangles. In addition, the sine and cosine laws of triangles are defined.
Unit Plan
BBC

Bbc: Bitesize: Maths: 2 D Shapes

For Students 2nd - 8th Standards
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.
Handout
CK-12 Foundation

Ck 12: Geometry: Triangle Relationships Study Guide

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This study guide reviews terminology for triangles, triangle properties, different types of triangles, and interior and exterior angle theorems.
Handout
Math Open Reference

Math Open Reference: Isosceles Triangle

For Students 9th - 10th Standards
A reference guide to isosceles triangles. It provides a definition and interactive animated activity that enhances further explanation. Includes links to related topics.
Handout
Geometry Help

Geometry Help: Equilateral Triangles

For Students 9th - 10th Standards
Explains the basic concept of equilateral triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Handout
Math Open Reference

Math Open Reference: Equilateral Triangle

For Students 9th - 10th Standards
Learn about equilateral triangles with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Handout
Math Open Reference

Math Open Reference: Circumcircle of a Triangle

For Students 9th - 10th Standards
A complete reference guide to the circumcircle of a triangle. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Handout
Math Open Reference

Math Open Reference: Euler Line

For Students 9th - 10th
Learn about the Euler line with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.
Handout
Math Open Reference

Math Open Reference: Area of an Equilateral Triangle

For Students 9th - 10th Standards
Learn about the area of an equilateral triangle with this helpful reference tool. Provides a detailed definition, examples, and an internet activity that enhances further explanation. Includes links to related topics.
eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 5.5 Geometry Software for Constructions

For Students 9th - 10th Standards
Use interactive geometry software to construct an equilateral triangle that maintains its shape even if you move its vertices.
eBook
CK-12 Foundation

Ck 12: Interactive Geometry: 1.4 Triangles

For Students 9th - 10th Standards
Explore and measure a variety of triangles.
Handout
Quia

Ixl Learning: Types of Triangles

For Students 3rd - 5th Standards
Brush up on your math skills relating to the types of triangles then try some practice problems to test your understanding.
Lesson Plan
PBS

Pbs Learning Media: Triangles: Targeted Math Instruction

For Students 9th - 10th Standards
Students will learn how to apply the properties and characteristics of all triangles to solve real-world problems and identify and use the unique characteristics of right, isosceles, equilateral, acute, obtuse, and scalene triangles.
Unit Plan
E-learning for Kids

E Learning for Kids: Math: Riksjas, Toek Toek: Polygons

For Students 5th - 6th
Explore polygons with Wang, a ricksha puller. Answer his questions and he will give you a free ride!
Lesson Plan
Science and Mathematics Initiative for Learning Enhancement (SMILE)

Smile: Polyhedrons

For Teachers 9th - 10th Standards
This in-depth paper examines the idea of convexity. Euclid's Elements, the first geometry textbook, assumed convexity without mentioning the term.
Activity
Other

Ic Teachers: Shapes: Triangles

For Students 6th - 9th Standards
Are you looking for a very basic website that will explain the basic properties of a triangle? Use this site to learn about the properties of equilateral triangles, isosceles triangles, right triangles,and scalene triangles. There are...