  In 1974 Cvetkovi\'c and Simi\'c showed which graphs $G$ are the bipartite
complements of line graphs. In 2002 Borovi\'canin showed which line graphs
$L(H)$ have third largest eigenvalue $\lambda_3\leq0$. Our first observation is
that two of the graphs Borovi\'canin found are the complements of two of the
graphs found by Cvetkovi\'c and Simi\'c. Using the Courant-Weyl inequalities we
show why this is and reprove the result of Borovi\'canin, highlighting some
features of the graphs found by both.
