some famous mathematical problems featuring pi

Area = (pi)radius2 Circumference = (pi)diameter The cosmological constant Heisenberg's uncertainty principle Einstein's field equation of general relativity Coulomb's law for the electric force, describing the force between two electric charges (q1 and q2) separated by distance r Magnetic permeability of free space Kepler's third law constant, relating the orbital period (P) and the semimajor axis (a) to the masses (M and m) of two co-orbiting bodies. Hope this will help you.