# Highschool Geometry: Finding Common Tangent

I can't seem to identify what the arrows are indicating in this question, obviously the two lines are parallel but what does it mean? I don't know where to begin.

Any suggestions?

• One of the common tangents is the $x$-axis. – André Nicolas Apr 13 '15 at 21:01
• Ah! I see, thank you all – IAmAlfred Apr 13 '15 at 21:19