Pythagoras Theorem
                    
                        Pythagoras Theorem applies to right angled triangles.
                    
                        A right angle triangle - Figure to the right - is a triangle with one angle
                        equals to 90°. The side opposite to this angle is known as the Hypotenuse.
                        For angle A, side b is known as the adjacent and side a
                        is known as the opposite.
                        Equally, for angel B, side a is known as the adjacent and side
                        b is known as the opposite.
                    
                    
                        Pythagoras' theorem states that for all right angle triangles "The
                            square constructed on the longest side - hypotenuse- of the triangle,
                            is equal to the sum of the squares constructed on the other two sides of the triangle"
                        
                        Example: A triangle with sides 5,4 and 3. 52 = 42
                            + 32 as shown in the Fig 2.
                        The inner radius, r, the radius of a circle inside the triangle, is given
                        by the following formula from Fig 1: r = a * b / (a + b + H)
                        The outer radius, R the radius of a circle surrounding the triangle is R =
                            H / 2.