Final answer:
If the duration of an owner's rights in an estate cannot be determined, the owner possesses an indeterminate legal estate.
Step-by-step explanation:
The subject of the question is Humanities.
If the duration of an owner's rights in an estate cannot be determined, the owner possesses an indeterminate legal estate. An indeterminate legal estate refers to a situation where the duration of the owner's rights is uncertain. This can happen when there is no specific end date or condition stated in the ownership arrangement.