The formal bond angles around the central atom (carbon) in CH3I are approximately 109.5 degrees.
In CH3I, carbon is bonded to three hydrogen atoms and one iodine atom. The geometry is dictated by the VSEPR (Valence Shell Electron Pair Repulsion) theory, which states that electron pairs around a central atom will arrange themselves to be as far apart as possible to minimize repulsion.
In this case, the carbon atom has four bonding pairs of electrons (three from hydrogen and one from iodine) and no lone pairs. This arrangement leads to a tetrahedral geometry. In a perfect tetrahedral shape, the bond angles are 109.5 degrees. However, the presence of iodine, which is larger and more electronegative than hydrogen, can cause a slight distortion in the bond angles, but they will still be quite close to 109.5 degrees.