Answer:
HM = 3 or HM = 15
Explanation:
The product of segment lengths is the same for both chords.
Setup
FM·EM = GM·HM
GM +HM = 18
Substituting for GM, we have ...
FM·EM = (18 -HM)·HM
5·9 = (18 -HM)·HM
Solution
Effectively, we want two factors of 45 that have a total of 18. Looking at the factors of 45, we have ...
45 = 1·45 = 3·15 = 5·9
The totals of these pairs are 46, 18, 14. The factor pair we're looking for is 3·15.
Either of these factors could be HM. The other will be GM.
There is nothing in the problem description that suggests the length of HM relative to other lengths on the diagram. (We know the diagram is not to scale.) So, there are two possible solutions:
HM = 3 or HM = 15