finding the apothem of an octagon

[USCfan_10704]

:?: how do you find the length of the apthem ofa regular octagon whose sides are each 10 inches long. i have so far
Tan 67.5=x/5 but that answer keeps coming up around 112 and i know that cant be right can someone please help me?

[TchrWill]

You have the right expression but must be misusing your calculator.

tan(67.5) = x/5

x = 5tan(67.5) = 5(2.4142) = 12.071.