Why did you think 12.8?
i followed this formula http://assets.openstudy.com/updates/attachments/5604608ee4b032660b1f9dfa-happy_to_help-1443127627952-distance.gif
I got 10 - I just counted the units diagonally. :P I could definitely be wrong. What kind of class is this? Geometry or Algebra?
That's a heck of a formula. I'm in geometry and they haven't given me formulas like that quite yet o.o
12.8 is the distance between the high school and the library. The question however asks for the distance between Tina's home and the HS. Note that it's given that Tina live exactly between the HS and the library.
Nice illustration :)
The formula is called 'the distance formula' and is basically the Pythagorean theorem. More on that here: https://www.mathsisfun.com/pythagoras.html
thankyou so much i understand it now :)