The Illusion that Mathematics 'EXPLAINS' facts

Let me give you an easy example, suppose you have a square to pave in the yard of a lady who wants you to isolate some how that square for the remaining yard because she does not want vegetation planted inside that area ( or any other reasom she may have to ordeer this job) and you must delimit that area with something. Wahtever you are going to put there you need to compute how much material you need and in order to do that you must multiply the lenght of any side of the square by 4 ( the sides of a square are all the same measure). Suppose that in the middle of your work the lady comes to you and says that instead of a squared area she wants a circle, which has a diameter whose lenght is identical with the original square. Now if you know geometry you also know that you must multiply the measure of the side of the original square ( now a cricle) by a little less than 4, i.e. 3.14 also known as PI ( the greeck letter!). Why is that? There is nothing miracolous about 3.14. It has simply noticed that if you construe a circle with a diameter = to the size of a preexisting square and you want to know the lenght of the circonference, the original lenght of the perimeter of the square is shortened by the distorsion of the gemoetrical figure into a circle and the difference is in favor of the square is 0.86, hence 3.14 is the new constant (3.14+0.86=4) !!!! The formula for calculating the circumference of a circle is: C=2rp where r is the radium that multiplied by 2 is the diamater and p is 3.14. This is universal in the sense that you must know the axioms of the Euclidean gemotry and our decimal number system to recognize the formula. There is no explanation of anything, just the expression of a constant >>>3.14. Rather than explaining, mathematics needs to be explained in order to uderstand what kind of useful tool it is!!!