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...

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.

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.

This resource provides information about the altitude theorem for equilateral triangles, in addition to links on related topics. Requires Java.

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.

Suppose we are given a circle of radius r. The goal of this task is to construct an equilateral triangle whose three vertices lie on the circle. Aligns with G-CO.D.13.

In this task, young scholars 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.

This activity illustrates the multiple representations of the attributes of triangles with their vertices on an equilateral hyperbola analytical, graphical and dynamic; addressing various conceptual levels of the students Using CAS.

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...

This task examines how to calculate the area of an equilateral triangle two ways: using triangle congruence and using trigonometric ratios. Aligns with G-CO.C.10 and G-SRT.C.

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.

Given an equilateral triangle, students are asked to explore its symmetries using rigid transformations of the plane. Aligns with G-CO.B.

This task examines some of the properties of reflections of the plane which preserve an equilateral triangle. The task gives students a chance to see the impact of these reflections on an explicit object and to see that the reflections...

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.

This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 5 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."

This lesson will define scalene, isosceles, and equilateral triangles. It is 1 of 5 in the series titled "Scalene, Isosceles, and Equilateral Triangles."

An equilateral triangle is a special case of a triangle where all 3 sides have equal length and all 3 angles are equal to 60 degrees.

This geometry lesson defines equilateral, isosceles, and scalene triangles, and has a variety of exercises, including drawing exercises.

The purpose of this task is to explore reflections in the context of paper folding. Each fold is associated with a line of reflection and understanding each step in the construction requires careful analysis of angles and of the...

The purpose of this task is to apply knowledge about triangles to calculate the sine and cosine of 30 and 60 degrees. Aligns with HSF-TF.A.3.

[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.

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...

This picture shows an equilateral triangle, a three sided regular polygon with internal angles of 60 degrees and sides of equal length.

Use interactive geometry software to construct an equilateral triangle that maintains its shape even if you move its vertices.