



 
Hi Roberto, What I see is this where each of the long sides is 20 feet long and the measure of each of the internal angles is 135 degrees.If this is correct then I need more information to determine the lengths of the six shorter sides. In particular do you know the distance between the long sides? Penny Roberto wrote back.
Sides of length 6.67' will certainly work, I just thought that the width of the "ring" might be important. Once you know one you can determine the other. Suppose $d$ is the distance between the long sides as in the diagram below and $x$ is the lengths of the short sides. The triangle $ABC$ is an isosceles right triangle with the length of the hypotenuse $x$ feet and thus Pythagoras Theorem says that the length of $AC$ is $\frac{x}{\sqrt 2}$ feet. Thus \[d = 2 \times AC + x = \sqrt 2 x + x = \left(1 + \sqrt 2 \right) x.\] Hence if $x = 6.67$ feet then $d = 16.10$ feet. Penny  


Math Central is supported by the University of Regina and the Imperial Oil Foundation. 