Answer:
1) 50%
2) 0%
Explanation:
If the gene for dwarfism is dominant, then the father has a genotype of Dd or DD
1) if it's Dd as his genotype then it would be a Dd and dd cross which gives you Dd, Dd, dd, and dd, half of which is dd, which means you will get a 50% probability of having a normal child
2) if it's DD for his genotype then it would be DD and dd cross which gets you Dd for all four Punnett squares, so it'll give you a 0% probability of having a normal child