Compare 2 variables if the range is bigger than a number

I am trying to make an if-else statement that does the following:

varName1 = 5.0
varName2 = 7.6

I need to compare 2 variables to each other and get the different output when the range between them is lesser or bigger than 2.5.

I have been trying and searching for a couple of hours now but I can not find a solution.