Can someone help me solve this math problem?

Question

brinazarski · Answer

I'll post it in a second

brinazarski · Answer

http://i158.photobucket.com/albums/t120/brinazarski2/w_zpsa586a596.png

anonymous · Answer

are there any equations you know for the area of a regular octagon that might help us.  its been a while since i took geometry.

brinazarski · Answer

Same here :/

anonymous · Answer

one sec

brinazarski · Answer

Okay

anonymous · Answer

im looking at this webpage (around the middle of the page) where it talks about the area of the octagon. http://www.mathwords.com/a/area_regular_polygon.htm

brinazarski · Answer

Looks pretty complex... and from that i have to find the area of the "rectangle" inside it.

brinazarski · Answer

"Measure one side of a regular octagon. Figure the area of a regular octagon using the formula A= 2(1 + √2)S² where S is the length of a side and A is the area."

brinazarski · Answer

I got that from Googling...

brinazarski · Answer

S^2 = 1/(2+ 2rad2)...?

brinazarski · Answer

so one side would be the square root of that...?

anonymous · Answer

yes

brinazarski · Answer

well, i still got the wrong answer...

brinazarski · Answer

i got 2/(2 + rad2)

brinazarski · Answer

but that's not a choice

anonymous · Answer

that's because you need to find the apothem, not the side length.  the apothem is the perpendicular distance from the center of the polygon to one of the sides.

brinazarski · Answer

but i did

brinazarski · Answer

it's a rectangle, you need the side length and that thingy

brinazarski · Answer

i found that thingy to be 2(rad(1/(2_rad2)))

brinazarski · Answer

and then i multiplied it with the side and got my answer

brinazarski · Answer

even with the formula for it, i still need the radius, and i do not know how to find the radius...

anonymous · Answer

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