A hint to get started
Drop a normal from a point and reflect through its foot
A plane passes through and and is parallel to the line , .
(i) Find the foot of the perpendicular from to the plane.
(ii) Hence or otherwise find the shortest distance from A to the plane.
(iii) Find the image of A reflected in the plane.
CJC · Discussion · Question 4
Find the normal first; the perpendicular foot lies both on its line through A and on the plane.