digraph G {
  a -> b -> c;
  b -> d;
  a [shape=polygon,sides=5,peripheries=3,color=lightblue,style=filled];
  c [shape=polygon,sides=4,skew=.4,label="hello world"]
  d [shape=invtriangle];
  e [shape=polygon,sides=4,distortion=.7];
}