Based on this information, what is Thistle's phenotype for the fleece type trait?
a hairy fleece FF
This passage describes the fleece type trait in sheep:

In a group of sheep, some individuals have a hairy fleece and others have a woolly fleece. In this group, the gene for the fleece type trait has two alleles. The allele F is for a hairy fleece, and the allele f is for a woolly fleece.
Thistle, a sheep from this group, has a hairy fleece. Thistle has two alleles for a hairy fleece.
All organisms have pieces of hereditary material called genes, which are passed from parents to offspring. Genes contain instructions for building the parts of an organism. An organism's genes affect its observable traits, including its appearance, its behavior, and which diseases it may have. Genes may have different alleles, or forms, that can cause different versions of a trait.
For example, flower color is a trait in pea plants. The gene for this trait has two possible alleles. Each allele is represented by an uppercase or lowercase letter. The allele F is for purple flowers, and the allele f is for white flowers. Each pea plant has two alleles for the flower color gene—one allele inherited from each parent.
An organism's genotype for a gene is its combination of alleles for that gene. So, a pea plant may have a genotype of FF, Ff, or ff for the flower color gene.
An organism's phenotype for a trait is its observable version of that trait, which depends on the organism's combination of alleles. A pea plant may have a phenotype of purple flowers or white flowers for the flower color trait.
An organism's phenotype for a trait is its observable version of that trait. Thistle's observable version of the fleece type trait is a hairy fleece. So, Thistle's phenotype for the fleece type trait is a hairy fleece.