Postscript("25-pentagoni.ps",1.9,1.2)
Grafica(c(-1.1,2.3),c(-1.1,1.1))
Rettangoli(-1.1-1.1i,3.4,2.2,
  coloreri="yellow")
par(lwd=5) # Matita spessa.
angoli=pi/4+seq(0,2*pi,2*pi/5)
poligononero=cos(angoli)+1i*sin(angoli)
lines(poligononero)
z45=cos(pi/4)+1i*sin(pi/4)
poligonorosso=z45*poligononero
par(col="red")
lines(poligonorosso)
poligonoverde=0.5*poligonorosso+0.2
par(col="green")
lines(poligonoverde)
par(lwd=2)
centri=1.7+1i*seq(-0.55,0.55,0.25)
Cerchi(centri,0.3,
  coloreri="forest green",colore="red")
dev.off()