hopefully this is right or embarrassing
Basically Punnett Squares gives 4 possible outcomes so the ratio will always be 4:0, 3:1. 2:2 for a regular allele. In this case its heterozygous because only 25% will have the recessive allele. The second case is a bit harder but that one has codominance. You can tell because the genotypic ratio that a Punnett Square can give are 4:0, 2:2, 1:2:1 (idk if I'm missing any but they're the main), so if the phenotypic ratio is one of these but not one of the main genotypic ones it can't be regular allele. You have to understand the possibility of codominance in this case but this question is mainly just about the ratios.