Final answer:
In a 4x4 grid, there are 9 rectangles when squares are considered as rectangles.
Step-by-step explanation:
In a 4x4 grid, there are 9 rectangles.
To count the number of rectangles, we can use the formula: Number of rectangles = (Number of horizontal lines + 1) x (Number of vertical lines + 1).
Applying this formula to the given 4x4 grid, we get: (4 + 1) x (4 + 1) = 5 x 5 = 25. However, this count includes the 16 squares, so we need to subtract them from the total. Therefore, the number of rectangles in a 4x4 grid is 25 - 16 = 9.