If the magnitudes of →a,→b and ∣∣→a+→b∣∣ are respectively 3,4,5 then the magnitude of ∣∣→a−→b∣∣
The magnitudes of vectors →A,→Band→C are 3, 4 and 5 units respectively. If →A+→B=→C, the angle between →A and →B is