function to calculate area of triangle
def area ( x1 , y1 , z1 , x2 , y2 , z2 ) : NEW_LINE INDENT area = math . sqrt ( ( y1 * z2 - y2 * z1 ) ** 2 + ( x1 * z2 - x2 * z1 ) ** 2 + ( x1 * y2 - x2 * y1 ) ** 2 ) NEW_LINE area = area / 2 NEW_LINE return area NEW_LINE DEDENT