Area of a triangle using determinants
Matrices and determinants (introductory) · Mathematics
Study notes
Q: Find the area of the triangle with vertices (1,2), (4,6), (7,2). Are (0,0), (1,1), (2,2) collinear? Area = (1/2)|1(6-2) + 4(2-2) + 7(2-6)| = (1/2)|4 + 0 - 28| = (1/2)(24) = 12. Collinear check: (1/2)|0(1-2) + 1(2-0) + 2(0-1)| = (1/2)|0| = 0. Yes, collinear.