Find the number of rectangles excluding squares from a rectangle of size 9 × 6.

Explanation

To find the number of rectangles excluding squares from a rectangle of size 9 × 6, we can follow these steps:

### Step 1: Calculate the total number of rectangles
To find the total number of rectangles in a rectangle of size 9 × 6, we need to determine how many horizontal and vertical lines we can draw.

- A rectangle of size 9 × 6 has 10 horizontal lines (9 + 1) and 7 vertical lines (6 + 1).
- The number of ways to choose 2 horizontal lines from 10 is given by \( \binom{10}{2} \).
- The number of ways to choose 2 vertical lines from 7 is given by \( \binom{7}{2} \).
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