Hi 3 rectangles: 12cm by 14cm 3(12*14) = 504cm^2 One example of picking an object to cover the three rectangles would be squares 2cm by 2cm (6 across the bottom and 7 rows of them for each rectangle) That would take 3(42) or 126 to cover all three rectangles. 126(4cm^2) = 504cm^2 checks. Wish You the Best in your Studies.