Answer:
A punnet square can be described as a diagram which illustrates the outcomes of a cross.
Let's consider the alleles in bob squarepants is Ss and the alleles for his partner spongebabra are ss. The punnet square can be drawn as follows:
s s
S Ss Ss
s ss ss
The results from the punnet square show that there is a 50% chance that the offsprings will be heterozygous for square shape just like squarepants. There is also a 50% chance that the offspring produced will be round like spongebarbra.