please explain your answer so I can understand

Answer:
Shelly has to pay $1,110 to put a child safety fence around the edge of her swimming pool.
Step-by-step explanation:
First, you would find the perimeter of Shelly's swimming pool. To do this, you would add 25 + 16 + 17 + 16. You get 74 ft.
Then, you would multiply the 74 ft by the $15. Shelly has to pay $1,110 to put a child safety fence around the edge of her swimming pool.
Answer:
$1,110
Step-by-step explanation:
First, find the perimeter of this trapezoidal shape.
Here the perimeter is the sum of 16 ft, 25 ft, 16 ft and 17 ft, which
comes out to 74 ft.
Since the unit cost of the fence is $15/ft, the total that this person must pay for the fence is
($15/ft)(74 ft) = $1,110