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A prism graph joins two copies of a cycle graph by matching corresponding vertices. The triangular prism graph is the three-cycle case, with six vertices and nine edges.

The triangular prism has six vertices and nine edges. Each edge lies in at most one triangle, so it has no rhombus; its two triangles show that it is not $K_{3,3}=T_2(6)$.

This is the prism graph built from two triangles.