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. 5^{2} = 4^{2}
+ 3^{2} 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.