let $r$ be a commutative ring with identity. we use $varphi (r)$ to denote the comaximal ideal graph. the vertices of $varphi (r)$ are proper ideals of r which are not contained in the jacobson radical of $r$, and two vertices $i$ and $j$ are adjacent if and only if $i + j = r$. in this paper we show some properties of this graph together with planarity of line graph assoc...
