[Add Maths]Coordinate Geometry

1.) A vertex of a square of side "a" is at the origin.
The inclination of the one of its sides is "b" .
Find the equations of the sides of the square.

2.) a) A line L: 2x-3y=1 is given.
Show that the coordinates (x,y) of any point on
the line L can be written as
x=2+3k , y=1+2k

b.) A point P on the line L is equidistant from the lines
2x+y+3=0 and x+2y+5=0.
Find the coordinate of the P using the result in (a).