Graphs and networks · Grade 11
In Grade 11 you learn: graphs and networks.
A graph is a set of points (vertices) joined by lines (edges). Graphs model road maps, social networks, circuits and timetables. Graph algorithms find shortest routes, cheapest connecting networks and efficient delivery rounds.
Key facts
- The degree of a vertex is the number of edges meeting it. The degrees always add up to twice the number of edges.
- Eulerian (a closed trail using every edge once): every degree is even. Semi-Eulerian: exactly two odd vertices.
- A connected planar graph satisfies Euler’s formula V − E + F = 2.