Hence the chromatic number Kn = n. Example 5 What is the matching number for the following graph? Solution Number of vertices = 9 80 We can match only 8 vertices. Matching number is 4. Example 6 What is the line covering number of for the following graph? Solution Number of vertices = |V| = n = 7 81 Line covering number = (\u3b11) \u2265 \u2308 \ud835\udc5b 2 \u2309 = 3 \u3b11 \u2265 3 By using 3 edges, we can cover all the vertices. Hence, the line covering number is 3.