2 10
Formula:
Number of rectangles = number of long-side segments * number of wide-side segments?
(Number of line segments = basic point * number of basic line segments /2)
Solve the problem:
Number of long line segments =(7*6)/2=2 1.
Number of wide-side line segments =(5*4)/2= 10.
The number of rectangles = 21*10 = 210.