Baldness in humans is a dominant, sex-influenced trait. This gene is on the autosomes, not the sex chromosomes, but how it is expressed is influenced by the person's sex (due to hormones present, etc.). A man who is BB or Bb will be bald and will be non-bald only if he is bb. A woman will only be bald if she is BB and non-bald if she is Bb or bb (it's almost like B is dominant in males and b is dominant in females). Actually, because of the influence of other sex-related factors, most women never become totally bald like men do, but rather, their hair becomes "thin" or sparse.
If two parents are heterozygous for baldness, what are the chances of their children being bald? Use a Punnett square to illustrate this. (Note: Because the sex of a person does make a difference in how the gene is expressed, you need to set this up as a dihybrid cross to account for the sex of the children.)