Answer:
A punnet square can be described as a diagram which depicts the outcomes of a cross. For the scenario discussed in the question, the punnet square can be drawn as:
g g
G Gg Gg
g gg gg
The results from the cross show that there is a 50% chance that the offsprings will heterozygous green eyes.
There is a 50% chance that the offsprings produced from these parents will have brown eyes just like the male parent.