• In graph theory, a planar graph is a graph that can be embedded in the plane, i.e., it can be drawn on the plane in such a way that its edges intersect...
    36 KB (4,589 words) - 21:30, 18 July 2025
  • Thumbnail for Four color theorem
    Four color theorem (category Statements about planar graphs)
    terms of graph theory, by considering it in terms of constructing a graph coloring of the planar graph of adjacencies between regions. In graph-theoretic...
    49 KB (6,333 words) - 23:09, 21 July 2025
  • Thumbnail for 1-planar graph
    In topological graph theory, a 1-planar graph is a graph that can be drawn in the Euclidean plane in such a way that each edge has at most one crossing...
    24 KB (2,757 words) - 12:14, 12 August 2024
  • Thumbnail for Dual graph
    mathematical discipline of graph theory, the dual graph of a planar graph G is a graph that has a vertex for each face of G. The dual graph has an edge for each...
    51 KB (6,607 words) - 00:16, 3 April 2025
  • Thumbnail for Outerplanar graph
    In graph theory, an outerplanar graph is a graph that has a planar drawing for which all vertices belong to the outer face of the drawing. Outerplanar...
    19 KB (2,089 words) - 08:10, 14 January 2025
  • Thumbnail for Graph coloring
    no two adjacent edges are of the same color, and a face coloring of a planar graph assigns a color to each face (or region) so that no two faces that share...
    70 KB (8,460 words) - 16:34, 7 July 2025
  • Thumbnail for Book embedding
    Book embedding (category Topological graph theory)
    In graph theory, a book embedding is a generalization of planar embedding of a graph to embeddings in a book, a collection of half-planes all having the...
    68 KB (8,167 words) - 00:16, 5 October 2024
  • path of two adjacent edges. In Vizing's planar graph conjecture, Vizing (1965) states that all simple, planar graphs with maximum degree six or seven are...
    23 KB (2,776 words) - 01:55, 20 June 2025
  • In graph theory, the thickness of a graph G is the minimum number of planar graphs into which the edges of G can be partitioned. That is, if there exists...
    11 KB (1,268 words) - 07:21, 30 June 2025
  • Thumbnail for Edge coloring
    Edge coloring (category Graph coloring)
    either its maximum degree Δ or Δ+1. For some graphs, such as bipartite graphs and high-degree planar graphs, the number of colors is always Δ, and for multigraphs...
    65 KB (8,472 words) - 14:53, 9 October 2024
  • In graph theory, an st-planar graph is a bipolar orientation of a plane graph for which both the source and the sink of the orientation are on the outer...
    4 KB (599 words) - 07:56, 18 August 2023
  • Thumbnail for Graph drawing
    the graph is planar, then it is often convenient to draw it without any edge intersections; that is, in this case, a graph drawing represents a graph embedding...
    33 KB (3,554 words) - 05:14, 15 July 2025
  • Thumbnail for Wheel graph
    every wheel graph is a Halin graph. They are self-dual: the planar dual of any wheel graph is an isomorphic graph. Every maximal planar graph, other than...
    5 KB (589 words) - 13:02, 14 May 2025
  • The theory of graph minors began with Wagner's theorem that a graph is planar if and only if its minors include neither the complete graph K5 nor the complete...
    35 KB (4,045 words) - 11:35, 4 July 2025
  • Thumbnail for Hamiltonian path
    vertices in the whole graph. Theorem—A 4-connected planar triangulation has a Hamiltonian cycle. Theorem—A 4-connected planar graph has a Hamiltonian cycle...
    19 KB (2,043 words) - 13:05, 14 May 2025
  • In graph theory, the planar separator theorem is a form of isoperimetric inequality for planar graphs, that states that any planar graph can be split...
    73 KB (10,072 words) - 06:45, 12 May 2025
  • Thumbnail for Erdős–Gyárfás conjecture
    special case of 3-connected cubic planar graphs (Heckman & Krakovski 2013) Weaker results relating the degree of a graph to unavoidable sets of cycle lengths...
    5 KB (473 words) - 00:43, 24 July 2024
  • Thumbnail for Forbidden graph characterization
    graph is planar (can be drawn without crossings in the plane) if and only if it does not contain either of two forbidden graphs, the complete graph K5...
    16 KB (1,155 words) - 23:27, 18 July 2025
  • Thumbnail for Goldner–Harary graph
    proved in 1975 that it was the smallest non-Hamiltonian maximal planar graph. The same graph had already been given as an example of a non-Hamiltonian simplicial...
    7 KB (750 words) - 06:26, 16 July 2025
  • Thumbnail for Polyhedral graph
    polyhedron. Alternatively, in purely graph-theoretic terms, the polyhedral graphs are the 3-vertex-connected, planar graphs. The Schlegel diagram of a convex...
    7 KB (836 words) - 01:34, 24 February 2025
  • In graph theory, the planarity testing problem is the algorithmic problem of testing whether a given graph is a planar graph (that is, whether it can...
    17 KB (1,840 words) - 01:51, 25 June 2025
  • bipartite graph with fewer crossings than the number given by Zarankiewicz? Universal point sets of subquadratic size for planar graphs Conway's 99-graph problem:...
    195 KB (20,033 words) - 13:09, 12 July 2025
  • apex graph is a graph in which one vertex can be removed, leaving a planar subgraph. The removed vertex is called the apex. A k-apex graph is a graph that...
    109 KB (16,011 words) - 12:09, 30 June 2025
  • Thumbnail for Three utilities problem
    a graph embedding in the plane. The impossibility of the puzzle corresponds to the fact that K 3 , 3 {\displaystyle K_{3,3}} is not a planar graph. Multiple...
    25 KB (2,764 words) - 20:16, 25 June 2025
  • Thumbnail for Kuratowski's theorem
    In graph theory, Kuratowski's theorem is a mathematical forbidden graph characterization of planar graphs, named after Kazimierz Kuratowski. It states...
    9 KB (1,074 words) - 22:34, 27 February 2025
  • Thumbnail for Circle packing theorem
    G. A maximal planar graph G is a finite simple planar graph to which no more edges can be added while preserving planarity. Such a graph always has a...
    30 KB (3,857 words) - 17:30, 23 June 2025
  • Thumbnail for Planar straight-line graph
    graph theory, a planar straight-line graph (or straight-line plane graph, or plane straight-line graph), in short PSLG, is an embedding of a planar graph...
    4 KB (456 words) - 02:54, 1 February 2024
  • the planar separator theorem can be used to show that n-vertex planar graphs have universal graphs with O(n3/2) edges, and that bounded-degree planar graphs...
    9 KB (865 words) - 02:51, 20 February 2025
  • string graphs was eventually proven to be NP-complete, implying that no simple characterization is likely to exist. Every planar graph is a string graph: one...
    13 KB (1,532 words) - 11:59, 15 July 2025
  • Thumbnail for Graph (discrete mathematics)
    vertices is 1. If a path graph occurs as a subgraph of another graph, it is a path in that graph. A planar graph is a graph whose vertices and edges can...
    28 KB (3,671 words) - 21:37, 19 July 2025