The [color=#0000ff][b]blue[/b][/color] and [color=#6aa84f][b]green[/b][/color] lines are parallel to each other, while the [color=#ff0000][b]red[/b][/color] line is perpendicular to them both.[br][br]

Record the slopes of the [color=#0000ff][b]blue[/b][/color] and [b][color=#6aa84f]green[/color][/b] lines.