The perimeter of a right triangle is 24 inch. Find the dimensions of the triangle if the sides are all whole number lengths.

My answer: 6, 8, 10

do I have to put a unit like inch or feet?

of course you do. The perimeter was in inches -- so are the sides.

Of course, you could use cm or miles or chains or light-years, but then the numbers would no longer be integers.

Yes, it is important to indicate the unit of measurement when providing the dimensions of the triangle. In this case, since the perimeter is given in inches, you should also include inches for the dimensions of the triangle. Therefore, the dimensions of the triangle are:

6 inches, 8 inches, and 10 inches.