Khan Academy: Linear Algebra: Determinant and Area of a Parallelogram

Video demonstrating that the area of a parallelogram created by graphing the column vectors of a 2x2 matrix is the equivalent to the absolute value of the determinant of the matrix. Pythagorean theorem, in conjunction with calculating a projection and dot products, is used to determine the height of the parallelogram. Dot products are used to calculate the area. [21:37]