Lag1989 task №5.27

To implement worldwide television communications, it is sufficient to have three Earth satellites rotating in a circular orbit in the plane of the equator from west to east and located relative to each other at an angle of 120 degrees. The periods of revolution of these satellites must be equal to the period of revolution of the Earth around its own axis. Knowing that the gravitational constant G and the mass of the Earth M, determine the radius of the orbit r and the linear velocity V of such satellites.