ABSTRACT.

An injective function \( f : V(G) \to \{T_0, T_1, T_2, \ldots, T_n\} \), where \( n = |V(G)| – 1 \), is said to be a Tribonacci cordial labeling if the induced function \( f^{*} : E(G) \to \{0,1\} \) defined by \( f^{*}(uv) = (f(u) + f(v)) \pmod 2 \) satisfies the condition \( |e_f(0) – e_f(1)| \le 1 \), where \( e_f(0) \) is the number of edges with label \( 0 \) and \( e_f(1) \) is the number of edges with label \( 1 \). A graph that admits such labeling is called a Tribonacci cordial graph. In this paper, we determine the Tribonacci cordial labeling of Triangular Snake Graph \( TS_n \), Double Triangular Snake Graph \( DT(S_n) \), Quadrilateral Snake Graph \( QS_n \), Double Quadrilateral Snake Graph \( D(QS_n) \), and Cycle Quadrilateral Snake Graph \( C(QS_n) \).