Changes in the Diameter of a Graph Number of Cycles A, B, C, and D graphs have respective diameters of 2, 3, 4, and 3. Adding a link on graph C between nodes 4 and 6 reduced the diameter by 1 (graph D). Share this:Click to share on LinkedIn (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Reddit (Opens in new window)