Younger students may benefit from an explicit suggestion that when printing on a printer with a rectangular build plate, if they’re having trouble fitting their object on the size of the build plate, consider rotating the object’s position on the build plate so that its longest axis is on a diagonal of the build plate.
Or, depending upon the object’s shape and the vertical height of the printer’s print volume, rotate the object so that the “long” axis points up.
Finally, again depending upon the object’s shape, if you are seeking to truly maximize the size of object you can print, rotate the object so that the longest axis is oriented along a diagonal of the print volume: not only along the diagonal of the print bed, but also with one end of the long axis of the object rotated “up” so that the object’s longest axis starts on one corner of the build plate and then extends up to the top of the build volume (above the opposite corner of the build plate). (Whether this is practical for printing a particular object is likely to depend greatly upon the shape of the object. In particular, printing in such orientation may require printing with significantly more support than otherwise.)
Actually computing mathematically what angle to rotate “up” from a diagonal along the build plate may be something for junior high students to compute in class. (But as a starting point, whenever the build volume forms a cube, the rotation angle “up” from a flat orientation along a diagonal of the build plate would be ~ 35.3° to achieve maximal length. However, the exact best angle to achieve the longest possible diameter will vary, depending upon the relative side dimensions of the rectangular prism of the printer’s build volume.)