Function to calculate area of parallelogram
float area ( float x1 , float y1 , float z1 , float x2 , float y2 , float z2 ) { float area = sqrt ( pow ( ( y1 * z2 - y2 * z1 ) , 2 ) + pow ( ( x1 * z2 - x2 * z1 ) , 2 ) + pow ( ( x1 * y2 - x2 * y1 ) , 2 ) ) ; return area ; }