Gravital force physics question dealing with space?

The gravital force Fsm that the sun exerts on the moon is perpendicular to the force Fem that the earth exerts on the moon. The masses are: mass of sun= 1.99 x 10^30kg, mass of earth = 5.98 x 10^24 kg, mass of moon = 7.35 x 10^22 kg. The distances are Rsm= 1.50 x 10^11 m and Rem = 3.85 x 10^8 m. Determine the magnitude of the net gravitational force on the moon?