# Math Help - Angles between lines

1. ## Angles between lines

Find the angle between x=2+3t, y= -1-t and x+3y=0
Been having trouble with this one, part of extra work.
thanks for the help

2. Originally Posted by monkius
Find the angle between x=2+3t, y= -1-t and x+3y=0
Been having trouble with this one, part of extra work.
thanks for the help
solving the y equaiton for t you get

$y=-1-t \iff t=-1-y$ then sub this into the equation for y to get

$x=2+3(-1-y) \iff x=-1-3y$

try putting both equations into standard form and what do you notice?

Good luck.