SOLUTION: how do I find the area of a triangle using a matrice? I know what the formula is and how to put the numbers in but where do I go from there?

Algebra ->  Matrices-and-determiminant -> SOLUTION: how do I find the area of a triangle using a matrice? I know what the formula is and how to put the numbers in but where do I go from there?      Log On


   



Question 237863: how do I find the area of a triangle using a matrice? I know what the formula is and how to put the numbers in but where do I go from there?
Answer by Photonjohn(42) About Me  (Show Source):
You can put this solution on YOUR website!
it is +- 1/2 times the matrix
x1 y1 1
x2 y2 1
x3 y3 1
where x1,y1 etc. are the cooridnates of vertex 1, etc. for 2 and 3.
Get the Determinate of that matrix and make it positive using + or- 1/2 times it. that is the area of the triangle.