http://www.thearealist.com/triangle-area/how-do-you-find-the-area-of-a-triangle-using-the-determinant-of-a-matrix-only-working-backwards Wed, 08 Feb 2012 12:47:59 -0500 http://wordpress.org/?v=2.8.4 hourly 1 http://www.thearealist.com/triangle-area/how-do-you-find-the-area-of-a-triangle-using-the-determinant-of-a-matrix-only-working-backwards/comment-page-1#comment-1970 Catalina_romania Fri, 05 Mar 2010 07:28:59 +0000 http://www.thearealist.com/triangle-area/how-do-you-find-the-area-of-a-triangle-using-the-determinant-of-a-matrix-only-working-backwards#comment-1970 I hope you'll understand what i'm going` to write (i'm from Romania, in the last year of high school) First of all, I would note the determinant of the matrix with D and the area with A , to simplify our work. The formula of the area is : A=1/2 * | D | the determinant looks like that : -5 1 1 0 2 1 -2 x 1 now, we'll solve the determinant with the triangle's formula => D= -10 + 0 -2 + 4 + 5x + 0 = -12 + 4 + 5x = 5x - 8 We know that A = 4 => 1/2 * | D | = 4 => | D | = 8 => 5x - 8 = 8 => x = 16/5 hope it will help you in some way<br><b>References : </b><br> I hope you’ll understand what i’m going` to write (i’m from Romania, in the last year of high school)
First of all, I would note the determinant of the matrix with D and the area with A , to simplify our work.
The formula of the area is : A=1/2 * | D |
the determinant looks like that :
-5 1 1
0 2 1
-2 x 1
now, we’ll solve the determinant with the triangle’s formula =>
D= -10 + 0 -2 + 4 + 5x + 0 = -12 + 4 + 5x = 5x – 8
We know that A = 4 => 1/2 * | D | = 4 => | D | = 8 => 5x – 8 = 8 =>
x = 16/5
hope it will help you in some way
References :

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