> Well, before you edited ur post, I actually did some research on it.

The edit was to ADD stuff; all I had before the edit is still there...

> If we make a point P at any random location in the triangle......

>there are infinite values which satisfy the equation z^2 = x^2 + y^2

Yes; BUT in your problem's case, P cannot be at random,

since z^2 = x^2 + y^2; so x,y,z MUST be sides of a right triangle.

> Putting those values in the equation

= x + y + z yields infinite values for a also.

So what? You get a in terms of x,y,z; that's what you have been asked to do...