Let the straight line L be y=kx+b, and substitute the coordinates of point P into b=k-2. D 1.d2 is a formula using the distance from a point to a straight line. I don't remember that I can turn pages, because L divides a quadrilateral into two parts with equal areas (not necessarily triangles), but whether it is three or four, its area is the base times the height, so the height is equal, that is, d 1=d2, so the k and b obtained by this method should take absolute values when solving the equation. Therefore,