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.