In this paper, we study gentle algebras that come from (m + 2)angulations of unpunctured Riemann surfaces with boundary and marked points. We focus on calculating a derived invariant introduced by Avella-Alaminos and Geiss, generalizing previous work done when m = 1. In particular, we provide a method for calculating this invariant based on the the configuration of the arcs in the (m + 2)-angulation, the marked points, and the boundary components.