Answer:
The correct answer is marked
Explanation:
The parallel sides left and right have measures 120 ft and 80 ft, respectively.
The measures of the equal-length slanted sides at top and bottom can be found from the Pythagorean theorem.
Each left-side end-point is 20 ft off the horizontal, and the horizontal distance is 140 ft. Then the Pythagorean theorem tells you the slant length is ...
√(20² +140²) = √20,000 ≈ 141.42 . . . ft
So, the perimeter is the sum of side lengths:
120 ft + 2×141.42 ft + 80 ft = 482.84 ft ≈ 482.8 ft