Find the angle between the lines `x-2y+3=0 and 3x+y-1=0`.

Find the angle between the lines x-2y+5=0 and x+3y-5=0 .

Find the angle between the lines 3x=5 and 3x+5y-2=0

Find the obtuse angle between the lines x-2y+3=0\ a n d\ 3x+y-1=0.

Find the angle between the lines 3x=5 and 3x+5y-2=0 .

Find the angle between the lines x+3y-8=0 and 2x-3y+6=0 .

If the point (a^(2),a+1) lies in the angle between the lines 3x-y+1=0 and x+2y-5=0 containing the origin,then find the value of a .

Find the acute angle between the lines 2x-y+3=0\ a n d\ x+y+2=0.

Find the angle between the lines x-2y+z=0=x+2y-2z and x+2y+z=0=3x+9y+5z