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Area of Pentagon (Posted on 2008-01-07) Difficulty: 3 of 5
ABCDE is a pentagon with
   |AB| = |BC|, |CD| = |DE|,

   /ABC = 150, /CDE = 30,

   and |BD| = 2.
Find the area of ABCDE.

See The Solution Submitted by Bractals    
Rating: 2.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution re: two ways (spoiler) | Comment 2 of 4 |
(In reply to two ways (spoiler) by Charlie)

Didn't need that complicated half-angle stuff:

4 sin 15 cos 15

of course is 2 sin 30 = 2 * .5 = 1.


  Posted by Charlie on 2008-01-07 13:53:58
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