7. Find all Pythagorean triangles with an area equal to (i) 78 ; (ii) 360.
7. Let $x, y, z$ be given by equation (6) and equation (7). The area $A=d^{2} r s(r-s)(r+s)$ of a right-angled triangle with sides $d x, d y, d z$. Trying to solve with $A=78,360$, it is found that no such triangle exists.