I don't get this question can someone help?

12,200 ft²

Step-by-step explanation:

The area of the lawn = the area of the trapezium - the area of the square

Note that area of a trapezium is h*(a+b)*(1/2), where h is the perpendicular height, and a and b are the top and bottom.

Note that the area of a square is l*w, where l is length and w is width.

Therefore, the area of the lawn = [h*(a+b)*(1/2)] + [l*w]

= [80*(100+140)*(1/2)]+[50*52]

= 9600+2600

=12200