Go directly to content
Math Open Reference
search
Home
Index
About
Contact
Comment
on this page
Email
this page
Support
this website at no cost to you
learn how
Triangles
Triangle definition
Internal angles
Exterior angles
Perimeter of a triangle
Area of a triangle
Area of a triangle with fixed perimeter
Heron's formula (for area of a triangle)
Hypotenuse of a right triangle
Medians of a triangle
Midsegment of a triangle
Triangle Inequality Theorem
Types of triangle
Acute
Obtuse
Isosceles
Scalene
Equilateral
Right triangle
Special right triangles
45° 45° 90° right triangle
30° 60° 90° right triangle
Pythagorean triples
The 3:4:5 pythagorean triple
Solving the triangle
Introduction. What does 'solving' a triangle mean?
Pythagoras Theorem and it's converse
A graphical proof of Pythagoras Theorem
The Centers of a Triangle
Triangle centers - an overview
Centroid
Circumcenter
Incenter
Orthocenter
The Circles of a Triangle
Incircle
Circumcircle
Triangle problems
Quiz: Test your knowledge of triangle types
The "Many Triangles" problem
The "Ball Box" problem
The "Three Satellites" problem
(C) 2007 Copyright John Page