how many squares are there in a 3x3 geoboard?
how many rectangles?
google is your friend
https://www.quora.com/How-do-you-calculate-the-number-of-squares-in-an-n-x-n-square-grid
how many rectangles?
https://www.quora.com/How-do-you-calculate-the-number-of-squares-in-an-n-x-n-square-grid