Why do the inequalities for planar graphs apply only if it is simple?

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For planar, simple, connected graphs, with v≥3, we have e≤3v-6. If the length of the smallest circuit is 4, e≤2v-4. etc The proof of the inequalities is based on Euler's Formula which relies only on the graph being connected and planar, why must the graph be simple to apply these inequalities?

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Hint: What's the smallest number of edges a face can have in a simple graph? In a non-simple graph?