I suspect you are talking about integers here, though you don't say so. These situations are called Pythagorean Triplets (In a triangle with 1 right-angle, the sum of the squares of the smaller sides equals the square of the longer side). The smallest (apart from 0,0 and 0) is 52 = 42 + 32. If you are not talking about integers then there is no limit on smallness (apart from 0,0,0).
25 (32 + 42 = 52)
25= 5*5 = (3*3)+(4*4)
16
16
12
25 is a square number, and the sum of 9 and 16 is 25. 9 and 16 are also square numbers.
25 (32 + 42 = 52)
25= 5*5 = (3*3)+(4*4)
10^2 = 6^2 + 8^2 ie 100 = 36 + 64
5
There are two solution: -3 and +2.
16
16
The smallest two digit number is 00 (a number used as a wire gauge) and the biggest is 99, so the sum of the biggest and smallest 2-digits numbers is 99 (99 + 00).
1+2=3
12
49