3. In space with orthogonal Cartesian coordinate system $O x y z$, the plane $\pi : 3 x - 2 y + 5 = 0$ is given. －Determine the coordinates of point $H$, the orthogonal projection of $P ( 4,2,1 )$ onto the plane $\pi$; －Determine the intersection of the line $s$ : $\left\{ \begin{array} { l } x - y + 1 = 0 \\ z - 2 = 0 \end{array} \right.$ with the plane $\pi$.