Final answer:
The prefix "peri-" means surrounding. It is used to indicate that something encloses or is around something else, as seen in the term 'perimeter'.
Step-by-step explanation:
The prefix "peri-" means surrounding. It is derived from Greek and is commonly used in various English words to denote something that is around or near something else. For example, the term 'perimeter' refers to the outside edge of an area, signifying the line that surrounds that area. The prefix 'peri-' does not mean beside, between, or within; it specifically implies the concept of enclosing or being around something. Perimeter is a math concept that measures the total length around the outside of a shape. To find the perimeter, you add together the lengths of all the sides. This works for any shape, including triangles, rectangles, pentagons, and even irregular polygons.