Well, to find your solution to this problem, I would subtract 84 from 32 = 52. I would divide the number by 2, which equals 26. So, side lengths are 32, 26, and 26.
Or, another one is that 2 sides have the length of 32, so 32+32=64. I would subtract 84 from 64 and get 20. So, side lengths are 32, 32, and 20.