If you have correctly stated the question, it is a trick question. If it is asked verbally in an interview I would just say I don't take off on taxiways, unless I'm drunk. And no, you do not use the scale at the bottom for anything that might involve runway distance information for anything pertaining to the operation of your aircraft. BTW, I'm not being mean, but that you even asked those questions; here are some more to ponder... 1) If there are 3 frogs on a log and one decided to jump off, how many frogs are on the log? 2) Who is buried in Grant's tomb 3) When was the war of 1812 4) If an airplane crashed on the border of the US and Canada on which side would they bury the survivors?