Math Planet
Math Planet: Pre Algebra: Triangles
Learn about the types of triangles by taking a look at an example and a video lesson.
Math Planet
Math Planet: Geometry: Parallelogram, Triangles Etc
Resource examines the area of geometric solids through examples and a video lesson. [0:39]
Mathigon
Mathigon: Geometry: Polygons and Polyhedra: Quadrilaterals
This lesson focuses on quadrilaterals which can fall into multiple categories based on the number of sides and the angles.
Mathigon
Mathigon: Geometry: Polygons and Polyhedra: Polyhedra
This lesson focuses on polyhedra; a polyhedron (the plural is polyhedra) is a 3-dimensional solid object that is made up of polygons. Euler's Polyhedron Formula: In every polyhedron, the number of faces (F) plus the number of vertices...
Mathigon
Mathigon: Geometry: Angles and Polygons: Drawing Triangles
This lesson focuses on the Triangle Inequality, when the sum of the lengths of any two sides of a triangle is greater than the length of the third. When this happens, the three sides cannot form a triangle.
Illustrative Mathematics
Illustrative Mathematics: G Co Inscribing an Equilateral Triangle in a Circle
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.
Illustrative Mathematics
Illustrative Mathematics: G Co Inscribing a Hexagon in a Circle
In this task, students inscribe a regular hexagon inside a circle and compare its area to that of the circle. Aligns with G-CO.D.13.
Illustrative Mathematics
Illustrative Mathematics: G Co Origami Equilateral Triangle
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...
Purple Math
Purplemath: Greek Letters and Their Names
When you are working with geometry and trigonometry, you will see a lot of Greek letters. It will be helpful to know how the names of these letters are spelled and pronounced.
CK-12 Foundation
Ck 12: Geometry: Isosceles Triangles
[Free Registration/Login may be required to access all resource tools.] Apply the properties of isosceles triangles.
CK-12 Foundation
Ck 12: Geometry: Isosceles Triangles
[Free Registration/Login may be required to access all resource tools.] This concept will teach students the properties of isosceles triangles and how to apply them to different types of problems.
Math Open Reference
Math Open Reference: Isosceles Triangle
A reference guide to isosceles triangles. It provides a definition and interactive animated activity that enhances further explanation. Includes links to related topics.
Geometry Help
Geometry Help: Equilateral Triangles
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.
Geometry Help
Geometry Help: Triangles
Explains the basic concept of triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Math Open Reference
Math Open Reference: Equilateral Triangle
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.
Math Open Reference
Math Open Reference: Area of an Equilateral Triangle
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.
CK-12 Foundation
Ck 12: Interactive Geometry: 8.5 Inscribed and Circumscribed Circles of Triangle
Learn how an inscribed circle is the largest circle contained within the triangle.
CK-12 Foundation
Ck 12: Interactive Geometry: 8.6 Quadrilaterals Inscribed in Circles
Understand that quadrilaterals that can be inscribed in circles are known as cyclic quadrilaterals.
CK-12 Foundation
Ck 12: Interactive Geometry: 4.5 Theorems About Concurrence in Triangles
Find out about some common centers of triangles.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.5 Quadrilaterals
Explore and measure a variety of quadrilaterals.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.4 Triangles
Explore and measure a variety of triangles.
PBS
Pbs Learning Media: Triangles: Targeted Math Instruction
Young scholars 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.
AAA Math
Aaa Math: Finding the Third Angle of a Triangle
Finding the third angle of a triangle becomes easier by the explanation and examples presented.
Wolfram Research
Wolfram Math World: Heptagon
MathWorld offers general information and definition of the heptagon, a seven sided polygon.