The dual graph G* of a planar graph G has the faces of G as its vertices, and there is an edge between the vertices of G* if an edge of G separates the faces of G that those vertices represent. The dual graph of the dual graph is the original graph. An example of a planar graph and its dual are:
A planar graph G
The dual graph of G
- fourfold table
- four humours
- Fourier analysis
- Fourier, Baron (Jean Baptiste) Joseph
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- Fourier, Jean Baptiste Joseph (1768–1830)
- Fourier, (Jean Baptiste) Joseph, Baron (1768–1830)
- Fourier number
- Fourier series
- Fourier sine series
- Fourier synthesis
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- Fourteen Points (8 January 1918)
- Fourteenth Amendment (1868)