So100+99+98+97+96+...+2+1=100 * 49+100+50 = 5050.

The green space in this community is too small. Is it 3 times bigger to add or subtract 2 cm?

If the side length of a square is x, rectangles are x+2 and x-2.

3(x+2)(x-2)=x*x

3x*x- 12=x*x

x*x=6

The area of a square is 6 and the area of a rectangle is 2.