Pythagorean Theorem help, I don't fully understand this question.

What is the length of stack P Q with bar on top ? Round to the nearest tenth of a unit.

http://static.k12.com/calms_media/media/1578500_1579000/1578501/1/b228a746cddf3f53e96faaa89f4d4574b415b5c0/MS_IMC-150122-130505.jpg

Question

Pythagorean Theorem help, I don't fully understand this question. 

What is the length of stack P Q with bar on top ? Round to the nearest tenth of a unit.

http://static.k12.com/calms_media/media/1578500_1579000/1578501/1/b228a746cddf3f53e96faaa89f4d4574b415b5c0/MS_IMC-150122-130505.jpg

genericnoodles · Answer

@LegendarySadist This one is a little different from yesterday, I used the same method and I was of by a few decimals.

thomas5267 · Answer

Stack PQ with bar on top?

genericnoodles · Answer

Its "PQ" with a Bar on top of it @thomas5267

anonymous · Answer

|dw:1431708602146:dw|

thomas5267 · Answer

This? $\vec{PQ}$?

genericnoodles · Answer

Thanks once again @LegendarySadist and yes that's what I was referring to.

thomas5267 · Answer

$\vec{PQ}$ represents a arrow of length PQ pointing from P to Q basically.