# Pythagoras Theorem Formula Calculator For Right Angles, Isosceles Angles, & Non-Right Angles

Pythagoras Theorem is a very fundamental principle in Mathematics and it is one of the basic formulas every mathematician ought to know. The formula was named after the Greek philosopher Pythagoras who lived from 570 to 495BC.

### Pythagoras Theorem Defined

Pythagoras theorem is one of the formulas used to find the unknown side of a right-angled triangle given that two sides are known. The triangle has three sides names opposite, adjacent, and hypotenuse. Pythagoras theorem states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the square of the other two sides of the angle. if the hypotenuse is denoted by h, and the other two sides are denoted by a, and b, then the formula would be :

`h2 = a2 + b2`

### Pythagoras Theorem For Non-Right Angled Triangles & an Isosceles Triangle

There is no Pythagoras formula for Nin-right angles triangles, and Isocscles triangles. The formula used is the Cosine angle and you can read more in our article.