The surface area of the square on one side is simply the product of its length and width dimensions. Notice that the given data is in inches while the area asked should be in centimeters. To maintain consistency of units, convert inches to cm first using the conversion 1 in = 2.54 cm
8.5 in * 2.54 cm/in = 21.59 cm
6.5 in * 2.54 cm/in = 16.51 cm
Area = (21.59 cm)(16.51 cm)
Area = 356.45 cm²