Can the Pythagoras theorem be applied to other polygons apart from squares in relation to right angular triangles? Is the sum of area of any regular polygon made in the two sides of a right angular triangle equal to the area of the same polygon made at the hypotenuse?
If so how to prove it? The area was equal to the semi circles with diameters of the hypotenuse and the other two sides, does it apply with any other regular shapes? Can it be proved with the original Pythagoras theorem or otherwise? 

yeah it can be !! Euclid proved it yes!!
if we consider the  a general term for area,
   $A = ka^2$ (where $a$ is a side length and $A$ is the Area, area of any polygon is              proportional to square of it's side)
$a^2+b^2 = c^2$ (Pythagoras theorem where $c$ is the hypotenuse)
then,
$ka^2 + kb^2 = kc^2$
if we take the area of any regular polygon constructed at sides $a,b$ and $c$ as $A,B$ and $C$, then
$A = ka^2$
$B = kb^2$
$C = kc^2$
then,
$A+B = C$
