Final answer:
Without additional information or a diagram, it is not possible to determine the size of angle BGH based on the given angle CHF.
Step-by-step explanation:
The problem statement does not provide enough information or context to determine what the size of angle BGH is, based on the given value of angle CHF being 122°. Typically, in geometry, the relationship between angle CHF and angle BGH needs to be clearly defined, for example by stating if they are complementary, supplementary, alternate angles, corresponding angles, or any other kind of geometric relationship. Without such information, or a diagram to infer the relationship, it is not possible to accurately determine the size of angle BGH.