So let's say the letter is D and d, of course lower case is the recessive and uppercase is the dominant trait.
The dominant trait is the stronger Gene who's trait will usually show in a hybrid phenotype.
The recessive trait is the weaker Gene who is trait is usually Hidden and a hybrids phenotype.
1 domaint and 1 recessive trait meaning it is,
Dd
According to to Mendel's Principle of Dominance,
Offspring that are hybrid for a trait will have only the dominant trait in the phenotype and then vice-versa.
In this situation, again we have a dominant and recessive trait meaning it is Dd meaning it is,
Heterozygous (hybrid)
I hope that helped you out!!
Any questions, feel free to ask me!!