Answer:
Tall head shape
Explanation:
Purebred means that the person has a homozygous genotype. So in the case of Patrick, his genotype would be homozygous dominant, TT. Patti is also homozygous because short head shape is a recessive trait and the only way for it to come out would be if she were homozygous recessive. Now we put that in a Punnet and let's see the results:
TT x tt
T T
t Tt Tt
t Tt Tt
So as you can see all the offsprings have a genotype of Tt. Since tall head shape is dominant it is what will be expressed so all the children would have a tall head shape.