GR1
Vertex Degree
顶点度数
Graph / 图论Grades G5 - G7
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What It Looks Like
Recognition signals — when you see these, think of this structure:
- 1Network or graph diagrams
- 2Questions about connections or links
- 3Counting edges or connections at points
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What It Really Tests
The core mathematical idea behind this structure:
The degree of a vertex is the number of edges connected to it.
顶点的度数是与其相连的边数。
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Why Students Get Stuck
Common mistakes to watch out for:
- ⚠Forgetting that each edge contributes to two vertices
- ⚠Miscounting connections
- ⚠Not using the handshaking lemma
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Your First Step
How to begin thinking about problems with this structure:
Count how many edges touch each vertex. Sum of all degrees = 2 × number of edges.
计算每个顶点连接多少条边。所有度数之和 = 2 × 边数。
Related Structures
These structures share similar patterns or thinking approaches: