equations of straight line

1).
A point P(3,4) and the line L: x+2y-20 = 0 are given Find the equations of straight lines which pass through P and make an acute angle Z with L , where tanZ = 1/3.

2).
L represents a family of straight lines passing through the point (2,3) .
(a) Find the equation of L.
(b) If L'' is a line of L having equal intercepts, find the equation(s) of L''.




please state the step clearly,,,thanks a lot