SOLUTION: What is the area of a decagon who's side lengths measure 4cm?

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Question 176636: What is the area of a decagon who's side lengths measure 4cm?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
The area of a regular decagon of side length a is either:

A+=+%285%2F2%29a%5E2+%2A+cot%28pi%2F10%29 or

A+=+%285%2F2%29a%5E2+%2A+sqrt%285+%2B+2%2Asqrt%285%29%29

Just plug in 4 for a and get to work on your calculator.

See Wikipedia (http://en.wikipedia.org/wiki/Decagon) for more info on decagons.