finding the apothem of an octagon

USCfan_10704

New member
Joined
Aug 24, 2005
Messages
1
:?: 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?
 
Apothem

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.
 
Top