Given the line $r \equiv \frac { x - 1 } { 2 } = \frac { y } { 1 } = \frac { z + 1 } { - 2 }$, the plane $\pi : x - z = 2$ and the point A(1,1,1), find:\ a) ( 0.75 points) Study the relative position of $r$ and $\pi$ and calculate their intersection, if it exists.\ b) ( 0.75 points) Calculate the orthogonal projection of point A onto the plane $\pi$.\ c) (1 point) Calculate the point symmetric to point A with respect to the line $r$.