The square ABCD is divided into three parts X, Y, and Z.
• Area of X = 288 cm².
• Ratio of X : Y = 1 : 4, so area of Y = 4 × 288 = 1152 cm².
• From the figure, parts X, Y, and Z together make the whole square.
• Total area = 288 + 1152 + (area of Z from figure).
• Total area = 2304 cm².
• Side of square = \(\sqrt{2304} = 48\) cm.
Final Answer: 48 cm