In this paper, we study the notion of approximate biprojectivity and left
φ
-biprojectivity of some Banach algebras, where
φ
is a character. Indeed, we show that approximate biprojectivity of the hypergroup algebra
L
1
K
implies that
K
is compact. Moreover, we investigate left
φ
-biprojectivity of certain hypergroup algebras, namely, abstract Segal algebras. As a main result, we conclude that (with some mild conditions) the abstract Segal algebra
B
is left
φ
-biprojective if and only if
K
is compact, where
K
is a hypergroup. We also study the approximate biflatness and left
φ
-biflatness of hypergroup algebras in terms of amenability of their related hypergroups.