If 3 different positive real numbers are given to you, let say, "a", "b" and "c",

then (I hope) they are the side lengths of the triangle.


If so, then you use the Pythagorean theorem and check if the square of the LARGER number is equal 
to the sum of the squares of the two other numbers.


Usually, in such problems, the assignment should say WHAT these numbers do represent.



In other case, three slopes may/can be given.

Then you check if one of the three given numbers is the NEGATIVE RECIPROCAL to some of the other numbers.