Here is a bit more which explains the reason you might be having trouble.

Which natural numbers occur as the area of a right triangle with three rational sides? This is a very old question and is still unsolved, although partial answers are known (for example, five is the smallest such natural number). This is an unsolved math problem and recent progress has come about through its connections with other important open questions in number theory.

Notice that math professor Dragan has NOT jumped into this one. ;-)


>>>Which natural numbers occur as the area of a right triangle with three rational sides?
>>>5 is the smallest number that can be used.
>>
>>Assuming you mean that all 3 sides must have an integer length, and the area must be an integer area, there are at least 2 such triangles:
>>
>>3-4-5, area 6
>>5-12-13, area 30
>
>I can't make any sense out of the question myself. Rational numbers are the set of all real numbers that can be written as a ratio of integers with a nonzero denominator. So the question seems to say that all three sides must be expressed as ratios (ie - rational). It is beyond my ken.