How to Figure Wall Length for Octagons
- 1). Measure and record the length of one side of the square area into which the octagon should fit. The width and height of the finished octagon will equal this length.
- 2). Multiply the length by 0.207. For a 10-foot square, for example, 10 feet times 0.207 equals 2.07 feet.
- 3). Multiply the result by 2 to find the length of the octagon's sides. For example, 2.07 feet times 2 equals 4.14 feet for each side.
Source...