How do you determine the lengths of the sides of the octagon

how do you determine the lengths of the sides of the octagon

Depends on what information you have been given. You can use basic triginometry to determine the side length if you have been given the distance from the center to an edge, or if you have been given the area.

From edge to edge it is 5m

From geometry the sum of a side length L plus two times L/sqrt(2):


5m = L+ \2 \frac L {\sqrt 2


Rearrange:


L = \frac {5m} {1 + \sqrt 2} = 2.07m

I was working on some project, I came up with a couple of formulas:
Divide the Length by 2.4154 = 1 side.
or
Multiply the Length X .414 = 1 Side.