Answer:
17.94
Step-by-step explanation:
The formula for a problem like this is
P W/2 -W^2
Multiply the perimeter by half of the width and then subtract the width squared.
7.8/2 This would give us 3.9
Then we multiply this by the perimeter
3.9x20.2 This leads us too 78.78
Then we subtract w^2
7.8X7.8 Is equal too 60.84
Then we subtract
78.78-60.84 This leads us too 17.94
