Given:
A. A line segment
B. A point
C. A line
D. A ray
Required:
To choose which following geometric objects has a definite length.
Explanation:
A line segment has two endpoints.
A line has no end point.
A line-segment has a definite length. But a line does not have definite length.
Therefore the option A is correct.
Final Answer:
A line segment has definite length.
