Let $r$ be the length of the shortest cycle in a graph $G$. When does $\dfrac{r}{r-2}=\dfrac{|E|}{|V|-2}$ Let $r$ be the length of the shortest cycle in a graph $G$. When does $\dfrac{r}{r-2}=\dfrac{|E|}{|V|-2}$
So far I've managed to establish, that the following equation is true for cyclic graphs $C_n$, because then $|E|=|V|=r$ so trivially it's true. But is there any other case when this is true?

Take for example the cycle $C_6$ and connect the vertices $1$ and $4$ by two more paths of length $3$. Then for resulting graph $r=6, |E|=12, |V|=10$.  
