Answer:
114.8 square ft
Explanation:
We want to find the area of the mulch under the swing set, which is in the shape of a trapezoid.
The area of a trapezoid is denoted by:
, where
and
are the bases and h is the height.
Here, the two bases are 12 and 15, while the height is 8.5 ft. Plug in these values:

≈ 114.8 square ft