Five circles are arranged in the following fashion ( Two rows of 3 circles in square arrangement with one end circle removed from the top row ). Circles are of same diameter and touching adjoining circles as per the diagram. Draw a line passing through A ( Centre of the first circle on the bottom row ) in such a way that it divides the five circles into two equal areas.

                           *                 *
                      *         *       *         *
                    *             *   *             *
                   *               * *               *
                  *                 *                 *
                   *               * *               *
                    *             *   *             *
                      *         *       *         *
         *                 *                 *
    *         *       *         *       *         *
  *             *   *             *   *             *
 *               * *               * *               *
*        A        *                 *                 *
 *               * *               * *               *
  *             *   *             *   *             *
    *         *       *         *       *         *
         *                 *                 *
       
      

(In reply to re(2): Equation spoiler by vswitchs)

You are right, of course. Silly me!  Somehow it's a lot more obvious to me if the radius is 1, though. There is no point in making the radius anything but 1, actually, since it can always be 1 "unit," whatever a "unit" might be (such as 2.7693 feet).

Edited on August 26, 2006, 2:39 pm

Posted by Richard on 2006-08-26 13:20:10