Answer:
50 feet long
Explanation:
Use the Pythagorean theorem to find the value of the missing side. The pythagoreon theorem only works with right triangles such as this one.
a²+b²=c²
Where a and b are length of legs (sides) of a triangle. And c is the length of the hypotenuse. The hypotenuse is the side across from the right angle.
We know by looking at the image posted in the question, that one leg of the triangle is 14 feet. And another leg is 48 feet. (Length of picnic area) (length of campground)
14²+48²=c²
Simplify
196+2304=2500
Find square root of 2500
√(2500)=50
So 14²+48²=50²
The missing side is 50 feet long. The fence is 50 feet long.
Attached is another example.