Perimeter

How to help

Add the lengths of all the sides. If one side is missing, take the other sides away from the perimeter.

• perimeterthe distance all the way around a shape
• sideone straight edge
• unitwhat a length is measured in: cm, in, ft
• missing sidethe one side you work out

Watch for: Multiplying the sides (that's area) instead of adding. Leaving out sides that aren't labelled. Forgetting the unit.

At home: Walk around a table or a rug and count your steps: that's its perimeter in steps.

Sample sheet and answer key

New problems every time, three levels (gentle, core and stretch), themes to pick from, a second page if you want one. Each sheet comes with an answer key and a one-page guide for grown-ups.

Standard

Common Core 3.MD.D.8 · Solve perimeter problems, including finding a missing side.

Also: Maryland 2025 3.GR.C.9 · Texas TEKS 3.7B · Florida B.E.S.T. MA.2.GR.2.2 · Virginia SOL 3.MG.2

Drill sheets for more practice

• Area and perimeter of rectangles

More grade 3 sheets: measurement & data

• Time to the minute
• Liters and kilograms
• Scaled graphs
• Measuring to ¼ inch
• What is area?
• Measuring area
• Area by multiplying