Cycle (graph)maths graph-theoryA cycle in a graph is path $\{e_i = (x_i, y_i)\}_{i=1}^{k}$ such that $x_1 = y_k$ and $e_i = e_j \Rightarrow i = j$. Visual representationLets use our simple graph below In this graph we have a cycle using the vertices $\{1,2,3\}$.