```Date: Jun 12, 2008 10:15 PM
Author: Al
Subject: Area problems

Im trying to teach myself some geometry on my own, but im stuck right now with a couple of area problem of triangles. I ll really appreciate any help or advice about it. The formulas for a triangle are:A=1/2 bh   and  A=1/2 ab Sen C  The problem says: -Find the area of a triangle with two adyacent sides that are 5 and 4 ,and they include an angle that is 45º  I thought that the formula might be A=1/2 ab Sen C so it would be A= 1/2 (4)(5)(sen 45) = 7.07106...but the result on the book was = 5 square root of 2Could I use sen of 45 in that way? if not waht is the correct procedure in order to do that problem? There are some other similar problems that I cant understand as well:-Find the area of a triangle with two adjacent sides that are 8 and 12, and they include an angle that is 60º.-Find the area of a triangle if two sides are 13 and 15, and the hight over the third side is 12.Im stuck with those ones, I 'll really appreaciate any help.Thanks a lot in advance.
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