What is a right triangle with its sides on x and y axis called?
In a right triangle, it does not matter whether zero, one, or two legs (the sides adjacent to the right angle) are on the $x,y$ axes. If the legs are equal, it is an isosceles right triangle. If all sides are different, it is a scalene right triangle. A scalene right triangle with integers for all sides is a Pythagorean triple. I know of no other names.