California Assessment of Student Performance and Progress (CAASPP) Math Practice Exam

In geometric terms, what do edges refer to?

1. Lines in a two-dimensional space

2. Points where shapes connect

3. Lines that connect the vertices of a three-dimensional figure

4. Shapes that have a closed boundary

The correct answer is: Lines that connect the vertices of a three-dimensional figure

Edges refer specifically to the lines that connect the vertices of a three-dimensional figure. In geometry, particularly when discussing polyhedra and other three-dimensional shapes, an edge is defined as the line segment formed between two vertices. Each edge provides the structural framework that defines the shape of the object. For instance, consider a cube; it has twelve edges, and each edge connects two corners (or vertices) of the cube. This means that understanding edges is crucial for visualizing and working with three-dimensional figures, as they serve as the boundaries along which the faces of the object meet. The other choices do not accurately capture the definition of edges in this context. Lines in a two-dimensional space refer to flat dimensions rather than the connections between points in 3D shapes. Points where shapes connect represent vertices, not edges. Meanwhile, shapes that have a closed boundary describe a different aspect of geometry related to the overall form, not specifically the lines forming that form.