Curated OER
Cabri Jr. - Getting Started with Triangles
Students explore a basic triangle construction. In this beginning geometry lesson, students investigate the steps to necessary to create an equilateral triangle with Cabri Jr.;
Curated OER
Expressions and Operations
In this expressions and operations worksheet, 9th graders solve and complete 3 different multiple choice problems. First, they determine the value that is closest to x for the given expression. Then, students find the height of an...
Curated OER
Expressions and Operations
In this expressions and operations instructional activity, 9th graders solve and complete 3 different problems that include identifying and applying various operations. First, they determine the value closest to the given expression....
Beacon Learning Center
Beacon Learning Center: Triangles Side by Side
This comprehensive web lesson describes how to classify triangles by their angle and side measurements. It provides real-world examples and exercises for students to practice the skill.
Crayola
Crayola: Exploring Triangles.
Here's a great geometry activity to display young scholars' knowledge of the different types of triangles. Provides resources and adaptations to supplement this lesson. (To access this lesson plan, you must register with Crayola.com....
National Council of Teachers of Mathematics
The Math Forum: Triangle Formulas
Investigate the geometric definitions of triangles, focusing upon equilateral, isosceles, right, and scalene with detailed drawings and appropriate formulas for each. This site has links to more information on triangles.
Oswego City School District
Regents Exam Prep Center: Angles and Triangles
On this site a viewer can learn about the different types of triangles, and categorized by either angles or sides. Tutorials are also included for interior and exterior angles of triangles. A teacher resource page includes a lesson plan...
Oswego City School District
Regents Exam Prep Center: Geometry Vocabulary Resources
A list of geometry definitions and a matching activity.
University of St. Andrews (UK)
University of St. Andrews: Biography of Hero
This University of St. Andrews site contains information on the life of Heron as well as his accomplishments.
Cuemath
Cuemath: Regular Polygon
Introduces the concept of regular polygons along with regular polygon examples, not regular polygons, irregular polygons, and area of a regular polygon. Check-out the solved examples for better understanding and try your hand at solving...
Cuemath
Cuemath: Equilateral
Learn all about the basic properties of equilateral. This lesson targets the meaning of equilateral, shows how to construct equilateral shapes, explores some of the equilateral shapes and properties, and how to apply them while solving...
Cuemath
Cuemath: Altitude of a Triangle
Explore the world of the altitude of a triangle in this mini-lesson including its definition, altitudes in different types of triangles, formulae, some solved examples, and a few interactive questions for you to test your understanding.
AAA Math
Aaa Math: Types of Triangles Based on Sides
Students can practice classifying triangles based on side lengths through a series of self-check exercises and timed learning games.
Duke University
Duke University: Web Feats Ii: Altitude Theorem for Equilateral Triangles
This resource provides information about the altitude theorem for equilateral triangles, in addition to links on related topics. Requires Java.
Texas Instruments
Texas Instruments: Constructing Triangles
This activity focuses on the various ways to construct the different types of triangles such as isosceles, equilateral, right, and right isosceles triangles. Students will begin by constructing triangles based on a minimal definition of...
Texas Instruments
Texas Instruments: Got an Equilateral Triangle? With Cabri Jr.
Using the Compass tool in Cabri Jr., students will construct an equilateral triangle, and check the length of each side. When a vertices is moved using the Alpha hand, the triangle remains equilateral.
Texas Instruments
Texas Instruments: Is an Equilateral Triangle a Special Case of Isosceles?
The definition of isosceles triangle can determine whether an equilateral triangle is a special case of an isosceles triangle. Using the Cabri Jr. application, students can get a feel for which definition makes the most sense. Along the...
The Math League
The Math League: Figures and Polygons
This site provides definitions of different types of polygons and figures.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Triangles and Angles
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of triangles and angles.
CK-12 Foundation
Ck 12: Geometry: 30 60 90 Right Triangles Problem Solving
[Free Registration/Login may be required to access all resource tools.] Identify special triangles and use the characteristics of 30-60-90 triangles in problem solving.
CK-12 Foundation
Ck 12: Geometry: Equilateral Triangles
[Free Registration/Login may be required to access all resource tools.] In this lesson students apply the properties of equilateral triangles. Students examine guided notes, review guided practice, watch instructional videos and attempt...
CK-12 Foundation
Ck 12: Elem Math: Classify Triangles, Composite Figures Number of Equal Sides
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on classifying a triangle inside a composite figure.
CK-12 Foundation
Ck 12: Geometry: Equilateral Triangles
[Free Registration/Login may be required to access all resource tools.] This concept will teach students the properties of equilateral triangles and how to apply them to solve problems. Students examine guided notes, review guided...
CK-12 Foundation
Ck 12: Equilateral Triangles
[Free Registration/Login Required] Students will move point B on the triangle to explore that all sides and angles remain the same. Click learn more to watch a video and click challenge me to answer a practice question.