Depends on what your objective is in sharing the file ...
... if your teacher needs to see all the part features, then you are out of luck. All major 3D modeling systems only have forward compatability; so you cannot save your file to a previous version.
... if your teacher only needs to see the finished part, then you can save it to one of the neutral 3D formats (like .sat) which can be read by previous versions. When using this type of file transfer, all of the Inventor specific information is essentially lost -- the file contains just enough information to recreate the final geometric shape but none of the history on how it was created or what special features (like tapped holes) were used.
HTH
iam or ipt File>Save Copy as type *.stp
Since your teacher didn't tell you this - you will probably have to show the teacher how to open the file.
It would make more sense for your teacher to upgrade their system to IV0214. They can then look at the current version files as well as open and inspect older versions.
Ok thanks I was just trying to give her the dimensions and all so I can have it printed on the 3D printer
You can save it as stl file for the 3D printer, be sure to click on Options and double check that the slt export file units are the same as your modeling units.