Answer:
10 feet
Step-by-step explanation:
The formula for the Perimeter fo a rectangle
= P = 2L + 2W
Where:
L = Length
W = Width
From the question
P = 80 feet
W = 30 feet
Hence:
80 = 2L + 2(30)
80 - 2(30) = 2L
80 - 60 = 2L
20 = 2L
L = 20/2
L = 10 feet
Hence, the length of the fenced area = 10 feet