In the figure below, how many rectangles are there that are not squares?
Lots try counting them systematically
1 x 2 ?
1 x 3 ?
1 x 4 ?
1 x 5 ?
2 x 3 ?
2 x 4 ?
2 x 5 ?
3 x 4 ?
3 x 5 ?
4 x 5 ?
that is it.
Please no one else interfer. Asker guest can do this by themselves now. How else will they learn?