Final answer:
Both a Hamiltonian circuit and a Hamilton path on a pencil and paper graph are typically indicated using continuous lines. A Hamiltonian circuit is drawn as a continuous loop that returns to the starting vertex, while a Hamilton path is an open curve that does not return to the start.
Step-by-step explanation:
In the context of pencil and paper graphs, a Hamiltonian circuit and a Hamilton path can both be indicated using continuous lines. A Hamiltonian circuit is a closed loop that visits every vertex in a graph exactly once and returns to the starting vertex. Therefore, it can be drawn with a continuous line that makes a complete loop without lifting the pencil. On the other hand, a Hamilton path also visits every vertex exactly once but does not return to the starting vertex, resembling an open curve which can also be drawn without lifting the pencil. On a graph, these can simply be indicated by tracing the path or circuit directly on the graph with a continuous line.
While other methods such as using dotted lines, different colors, or arrows could potentially be employed to differentiate these paths further, particularly in a more complex or educational setting, the key point is that both a Hamiltonian circuit and a Hamilton path are typically highlighted using a continuous line when being indicated on a paper graph.
It's important to note that the reference material provided regarding electric circuits, magnetic field lines, and electric field representations does not relate directly to the specific question about Hamiltonian circuits and paths, but they also use continuous lines to represent different elements in the graphs and schematics, reinforcing the use of this method in graph representation.