Mara decides to plot her neighborhood on a coordinate plane. She plots her house at the point (0,0), her school is located at (0,8), the library at (3,8), and the softball field is at (3,0). One day she decides that after school she will run by the library to grab a book, and then head to softball practice and then back home. How far on the coordinate plane does she travel starting at home that morning? Leave your answer in units.