mmm444bot, to answer your question in regards to;
It is because the results obtained by mathematics are susceptible of demonstration; ergo, it is the only field of thought in which an absolute truth can be established.
Now, if by using the formula for arc length, we discover that the length of a curled string is 5 ft.(results obtained by mathematics) and we stretch out the string, we will indeed find it to be 5 ft. long, ergo our results (5 ft. long) was proven by demonstration, hence an absolute truth was established, to wit: the string is 5 ft. long. Of course what is a foot? I am assuming that a foot has been defined and for those of you who are blind, perhap some tactile aid will assist you in understanding what we (who are not afflicked by your handicap) have defined as a foot.