Question

Which topological element represents start and end points of an arc?

• A. Node
• B. Polygon
• C. Sliver
• D. Vertex

Hint:

GIS Topology: \[ \boxed{ \begin{aligned} \text{Node} &\rightarrow \text{Arc endpoints} \text{Vertex} &\rightarrow \text{Shape of arc} \text{Polygon} &\rightarrow \text{Closed area} \end{aligned} } \]

Answer 1

The Correct Option is A

Concept: In GIS topology, an arc is a line feature that begins and ends at nodes. Nodes represent the start and end points of arcs and define network connectivity.

Step 1: Understand topological elements.
• Node $\rightarrow$ Start and end point of an arc.
• Vertex $\rightarrow$ Intermediate point defining the shape of an arc.
• Polygon $\rightarrow$ Closed area enclosed by arcs.
• Sliver $\rightarrow$ Small unwanted polygon formed due to overlay errors.

Step 2: Identify the correct element. Hence, \[ \boxed{\text{Nodes represent the start and end points of an arc}.} \] Therefore, the correct option is \[ \boxed{(A).} \]