Polygon Rule nonbonding line benzene cyclobutadiene cyclooctatetraene 2013 Pearson Educaton.inc The energy diagram for an annulene has the same shape as the cyclic compound with one vertex at the bottom. 2013 Pearson Education,Inc. Chapter 16 0 © 2013 Pearson Education, Inc. Chapter 16 10 Polygon Rule • The energy diagram for an annulene has the same shape as the cyclic compound with one vertex at the bottom