How many rectangles can you make out of 36 squares?

To determine how many rectangles can be formed from 36 squares, we can use the formula for counting rectangles in a grid. Each rectangle is defined by choosing two horizontal and two vertical lines. For a 6x6 grid (since 36 squares form a 6x6 arrangement), there are 7 horizontal lines and 7 vertical lines (including the edges). The number of rectangles is given by the combination formula: ( \binom{7}{2} \times \binom{7}{2} = 21 \times 21 = 441 ). Therefore, you can make 441 rectangles from 36 squares.