First of all, let me break down the formula:
is always a Pythagorean triple because you have

So, for any
you can choose (let's suppose
), these three numbers will always fall in the form
, which is also the rule that works for right triangles. So, every time you choose two numbers
, the legs will be
and
, while the hypotenuse will be
.
We have to find a right triangles with legs 16 and an odd number. Well, the legs in the triple we are given are
and
, so we want one of this to be 16, and the other to be odd. But
can't be odd, because it has a 2 factor in it. So, it must be 16: we have

The only ways we can choose two numbers
such that their product is 8 are:

In the first case, the legs are

In the second case, the legs are

In this case both legs are even, so the only good choice is 
So, the triangle we're working with has legs

and hypotenuse
