The polygon with the shortest perimeter for a given area is a regular polygon. The regular 4-sided polygon is the square.
The side length of the square with an area of 100 ft² is √(100 ft²) = 10 ft.
The rectangle with the minimum perimeter for an area of 100 ft² is 10 ft by 10 ft.
Using the Pythagorean theorem:
Hypotenuse = sqrt( 20^2 + 15^2)
Hypotenuse = sqrt( 400 + 225)
Hypotenuse = sqrt(625)
Hypotenuse = 25
Answer: 25 inches
