How many rectangles are thre in a 6 by 9 grid that are not squares?
To find the number of rectangles in a 6 by 9 grid that are not squares, we need to consider the different possible lengths and widths of the rectangles. We can use the formula for the number of rectangles in a grid, which is given by (m * (m + 1) * n * (n + 1)) / 4, where m and n are the lengths and widths of the grid.
In this case, we have a 6 by 9 grid. Let's plug those values into the formula:
(6 * (6 + 1) * 9 * (9 + 1)) / 4
= (6 * 7 * 9 * 10) / 4
= 1890 / 4
= 472.5
Since we cannot have half of a rectangle, we round down to the nearest whole number. Therefore, there are 472 rectangles in a 6 by 9 grid that are not squares.