Consider a planar graph G with 5 vertices a, b, c, d, e. In this order of the vertices, the adjacency matrix of G is
a b C d e
A = a 0 1 2 1 3
b 1 0 0 01
c 2 0 2 0 0
d 1 0 0 2 1
e 3 1 0 1 0
(a) How many edges does G have? Explain your answer based on the adjacency matrix A. Notes. Recall that loops are also edges.
b) Draw G and label/name its edges in your drawing. Notes. Planar graphs contain NO crossing edges.
(c) Write an incidence matrix of G according to the above order of the vertices. Notes. You choose some order of the edges.
(d) Draw a largest simple subgraph of G. Notes. A largest simple subgraph is a simple subgraph with the most vertices and edges.