Diagram of a 2-coloured K<sub>5</sub> without a monochromatic K<sub>3</sub>.
<a href="//commons.wikimedia.org/wiki/User:Joey-das-WBF" title="User:Joey-das-WBF">Johannes Rössel</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Joey-das-WBF" title="User talk:Joey-das-WBF"><span class="signature-talk">talk</span></a>)
2008-12-24
<span class="int-own-work" lang="en">Own work</span>