Curated OER
What is a Regular Polygon?
What makes a polygon a regular polygon? Does this mean there are irregular polygons? For a polygon to be classified as a regular polygon, all the sides must be congruent and all the angles must be congruent. Those are the two rules that...
Curated OER
What is a 30¡-60¡-90¡ Triangle?
Is it possible to take an equilateral triangle and cut it in half to make a 30-60-90 special triangle to make it easier to solve a problem? Why yes, of course! It's even possible to find the missing length without using the Pythagorean...
Massachusetts Institute of Technology
Mit: Blossoms: Arabesque: Where Art Meets Mathematics
Through a video lecture, students discover the visual side of the important applications of mathematics in practical life. More specifically, they will understand the relationship of mathematics and decoration or art.
Sophia Learning
Sophia: Equilateral Triangle Interior Angles Practice Problems: Lesson 1
This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 1 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."
Khan Academy
Khan Academy: Geometry: Problem Involving Angle Derived From Square and Circle
Demonstrates how to solve a challenging geometry problem about finding the measure of an angle that is formed by different segments in a square which intersect with part of a circle. Solution depends on creating triangles in the diagram...
Khan Academy
Khan Academy: Geometry: Equilateral Triangle Sides and Angles Congruent
In this video tutorial [6:29], the instructor models a proof so show that if the sides of an equilateral triangle are congruent, then all the angles are congruent and vice versa. The instructor uses the knowledge of congruent legs and...
Khan Academy
Khan Academy: Geometry: Common Orthocenter and Centroid
Proves that if the orthocenter and centroid are the same point in a triangle then the triangle is a right triangle. [6:25]
Khan Academy
Khan Academy: Geometry: Equilateral and Isosceles Example Problems
Demonstrates how to use the triangle sum theorem, properties of equilateral and isosceles triangles, and special angle pairs to determine the unknown measures of angles in three different diagrams. [6:27]
Sophia Learning
Sophia: Equilateral Triangles: Lesson 2
This lesson will prepare you to distinguish an equilateral triangle based on the sides of a triangle. It is 2 of 8 in the series titled "Equilateral Triangles."
Sophia Learning
Sophia: Equilateral Triangles: Lesson 8
This lesson will prepare you to distinguish an equilateral triangle based on the sides of a triangle. It is 8 of 8 in the series titled "Equilateral Triangles."
Sophia Learning
Sophia: Equilateral Triangles: Lesson 4
This lesson will prepare you to distinguish an equilateral triangle based on the sides of a triangle. It is 4 of 8 in the series titled "Equilateral Triangles."
Virtual Nerd
Virtual Nerd: Why Are the Angles of Equilateral Triangles Always Equal to 60 Degrees?
In this tutorial, learn how to find the measurements of the interior angles of an equilateral triangle. [5:02]
Khan Academy
Khan Academy: Triangles: Equilateral Triangle Sides and Angles Congruent
A video showing that all of the angles of an equilateral triangle are 60 degrees. The proof is written as a two-column proof.
Sophia Learning
Sophia: Calculating the Area of a Triangle
This video lesson demonstrates how to calculate the area of a triangle. It includes detailed examples including ones that use the Pythagorean Theorem. Students can check their understanding with an assessment. [10:43]
Sophia Learning
Sophia: Categorizing Triangles With Congruency
In this video tutorial, triangles are classified as isosceles, equilateral, and scalene by the congruency of their sides. Assess learning with a quiz. [1:52]
Sophia Learning
Sophia: Properties of Equilateral Triangle and Takin' It 2 the Streets
Use examples to solve for the angles of equilateral triangles in a PowerPoint presentation. Includes video. [4:18]
Sophia Learning
Sophia: Regular Polygons
Understand the what a regular polygon is and examples of regular polygons in this video tutorial. Assess learning with a quiz. [3:17]
Sophia Learning
Sophia: Scalene, Isosceles, and Equilateral Triangle
Explore types of triangles including scalene, isosceles, and equilateral in this video tutorial. [3:47] Quiz to follow to check understanding.
Sophia Learning
Sophia: Properties of Equilateral Triangles
Equilateral triangles are explored in this learning tutorial, which includes several videos [4:18; 4:18; 3:18] and a PowerPoint presentation. The lesson includes an introduction of equilateral triangles and their key characteristics....
Math Antics
Math Antics: Triangles
Gain a basic understanding of triangles by watching easy to understand video tutorial. Additional resources are available as part of a paid subscription service. [7:39]
Khan Academy
Khan Academy: Triangles: Area of an Equilateral Triangle
This video tutorial explores finding the formula for the area of an equilateral triangle with side length of s.
Sophia Learning
Sophia: Equilateral Triangle Interior Angles Practice Problems: Lesson 4
This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 4 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."
Sophia Learning
Sophia: Equilateral Triangle Interior Angles Practice Problems: Lesson 2
This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 2 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."
Sophia Learning
Sophia: Equilateral Triangle Interior Angles Practice Problems: Lesson 3
This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 3 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."