Answer: Yes, Talid's definition is valid.
Explanation:
- Definition of sphere:- In geometry , a sphere is a perfectly round three-dimensional shape . It is defined as the set of points that are all at the same distance which is known as radius from a given point in a 3-dimensional space.
- Talid's definition:- A sphere as the set of all points equidistant from a single point.
Hence, Talid's definition is valid.