Final answer:
To find the length of segment PR given PQ and QR, we use PR = PQ + QR since in geometry, lengths of connected segments sum up.
Step-by-step explanation:
To find the length of segment PR, we must consider the relationship between the lengths of segments PQ and QR. The correct way to determine the length of PR when given the lengths of segments PQ and QR is by using option A:
PR = PQ + QR
This is because in geometry, when two segments are joined end-to-end, the length of the entire segment is the sum of the lengths of the individual segments. No other operations such as subtraction, multiplication, or division are applicable in this context for simply finding the length of a connected segment. If PQ and QR are consecutive segments, then the total length PR is simply PQ plus QR.