In a chain survey work, in order to determine the length across a river of a continuing chain line, the following observations were made as shown in the figure. The points C, A, and B are collinear. Also, the points B, D, and E are collinear. CA = AD = 40 m. The angle CAD is 90°. Distance CE = 75 m, angle ACE = 90°. Determine length AB.