student asking the question
problem is college question (I think)

hello my name is brandy my husband and I would like to build an octagon shape flower bed to put around the tree in the front yard im currently taking math 70 in college right now but have no idea where to start for this one please help.
we would hope to have the whole shape about 4 ft-5 ft around the tree. what would be the way to find out how to cut each side to that they fit together equally
I thought maybe 135 divided by 8 but I don't think I could be that easy some one told me that they add up to 135 when all the sides are done
help help help
thank you for your time


Hi Brandy,

Octagons seem to be "the shape of the year". Sue has answered similar questions twice in the last few days. I am not quite sure what you mean by "4 ft-5 ft around the tree" so I have a diagram to try to help answer your question.

The relationship between w and s is

s = (√2 - 1) w = 0.414 w

You can see how to arrive at this relationship by examining Sue's answer to a similar question.

If w is 5 feet for the octagon you are constructing them

s = 0.414 5 = 2.07 feet

so cut eight pieces 2 feet long at an angle of 112.5o and they will fit together to form a hexagon.