Final answer:
The apostrophe next to a newly reflected point is referred to as a prime. When we reflect a point across a line or a plane, the new point is labeled with the original point's name followed by a prime symbol (').
Step-by-step explanation:
The apostrophe next to a newly reflected point is referred to as a prime.
When we reflect a point across a line or a plane, the new point is labeled with the original point's name followed by a prime symbol ('). This indicates that the new point is a reflection of the original point.
For example, if we reflect point A across the line to get a new point, we would label the new point as A', pronounced 'A prime'.