Find a suitable perimeter worksheet. There are tons of teaching websites, and they are relatively easy to find. A simple search that includes "worksheet" and "perimeter" will lead you to a number of links. For instance, LessonPlanCentral.com offers a number of printable worksheets with square and rectangle perimeter problems. SuperTeacherWorksheets.com and HelpingwithMath.com feature basic and more advanced (polygons, unlabeled sides) perimeter worksheets with answer keys.
Review the worksheet. Take a few minutes to look over it to make sure the problems are on par with the student's grasp of perimeter. He or she may not be up to the challenge of calculating polygon perimeters. If there is an answer key, make sure it is correct and the answers are not printed on the worksheet page.
Print out the math worksheet. Click the link to open the worksheet. Then print the entire page. Make sure to preview the page first to make sure the print is not too small or misaligned.