This paper gives the precise relationship formula of π with the square root of 2 and the square root of 3, i.e., 2^0.5+3^0.5=πγ with γ=1.00148705350035u2026, and gives the relevant approximation formula which we found in 2022, i.e., 1.41+1.73=3.14, in which 1.41, 1.73 and 3.14 correspond to the centigrade approximations of the square root of 2, the square root of 3 and π respectively. We also review the applications of the formula of 1.41+1.73=3.14 in our theories including the centigrade natural number axis, the new atomic units, the new periodic table of elements, the chirality model of atomic nucleus and the periodic table of nuclides, the formulas of the fine-structure constant, the formulas of the speed of light in atomic units, the predictions of the super-heavy elements and the formulas of the anomalous magnetic moments of electron, muon and tauon. And hence we conclude that the formula of 1.41+1.73=3.14 is not just a coincidence but is a basic principle in the sub-atomic world.