The problem of best approximation has been studied by many mathematicians. Most of these works have dealt with the existence, uniqueness and characterization of best approximations in spaces of continuous functions with values in Banach spaces. But little or no work on approximation has been done on 2-structures such 2-normed spaces, generalized 2-normed spaces and 2-Banach spaces. It is the aim of this paper to investigate the above two concepts in the sense of latter spaces. It is also to investigate the uniqueness and to give attention of this subject from this view.