Sub-tended is a word that is often used in mathematics and geometry to describe the relationship between two points on a curve or line. However, there are several synonyms for sub-tended that can be used to describe the same concept. These include intercepted, encompassed, contained, enclosed, and circumscribed. Each of these words has a slightly different connotation, but they all describe the idea of one thing being enclosed within or surrounded by another. By using these synonyms for sub-tended, writers and speakers can add variety and nuance to their language, while still conveying the same basic concept.