The Geometry of Triangles
Definitions and formulas for the area of a triangle, the sum of the angles of a triangle, the Pythagorean theorem, Pythagorean triples and special triangles (the 306090 triangle and the 454590 triangle)
Just scroll down or click on what you want and I'll scroll down for you!
examples of triangles  area of a triangle  sum of the angles of a triangle 
The Pythagorean Theorem  special Pythagorean triples 
special triangles 454590 & 366090 
Examples of triangles: 
The area of a triangle: 
The sum of the angles of a triangle: 
Always, always, ALWAYS! 
The Pythagorean Theorem:  
This formula is for right triangles only! The sides, a and b, of a right triangle are called the legs, and the side that is opposite to the right (90 degree) angle, c, is called the hypotenuse. This formula will help you find the length of either a, b or c, if you are given the lengths of the other two. 

Some special Pythagorean numbers:  
These are called Pythagorean triples.
The reason that they are so special is that they are whole numbers  none of those weird decimals, fractions or radicals! 
Special Triangles:  
The 306090 Triangle: If you have one side, you can use these formulas (and maybe a little algebra) to get the others. 

The 454590 Triangle: If you have one side, you can use these formulas (and maybe a little algebra) to get the others. 