Solving Perimeter Word Problems Worksheet

Perimeter is the distance all the way around the outside of a flat shape, and third graders meet it everywhere — a fence around a garden, a border around a bulletin board, trim around a rug. This Solving Perimeter Word Problems Worksheet takes that idea off the page and into real situations, so students add side lengths for a purpose instead of copying a formula. Working from a written story also asks children to decide what the numbers mean before they compute, which is exactly the reasoning third-grade standards expect.

This 3rd grade geometry worksheet gives students two kinds of practice on one page. Part A holds four short word problems about a square sandbox, a rectangular dog pen, a five-sided flower bed, and a triangular garden patch, each with a writing line for the answer. Part B raises the difficulty: students are told the perimeter of a rectangle and the length of its two long sides, then work backward to find the missing short side and explain their thinking on the lines provided. Use it as guided practice after a lesson, as morning work, as a quick check before a unit test, or as homework that parents can follow easily.

What’s Included

• 1 print-ready PDF worksheet
• Answer key
• 4 perimeter word problems plus 1 missing-side problem with a written explanation

There are three reasons this Solving Perimeter Word Problems Worksheet helps children learn. First, every problem names a real object with believable measurements, so students build a mental picture instead of guessing at which operation to use. Second, the shapes vary — square, rectangle, pentagon, triangle — so children learn that perimeter always means adding every side, not memorizing one rule for one shape. Third, the missing-side problem asks students to reverse their thinking and then justify it in writing, which turns a computation exercise into genuine mathematical reasoning.

Teachers and parents can stretch this skill well past the page. Hand students a tape measure and let them find the perimeter of a desk, a doormat, or a book, then compare their answers. Mark a rectangle on the playground with chalk and have children walk its perimeter, counting heel-to-toe steps for each side. Build shapes with craft sticks of equal length so the perimeter can be counted rather than calculated. For an extra challenge, give a perimeter and ask students to design as many different rectangles as they can that match it — a quick, playful introduction to the idea that shape and perimeter are not the same thing.

Related Resources

• Perimeter Word Problems Worksheet
• Finding the Perimeter of Shapes Grid Worksheet
• Perimeter Area Worksheet
• Polygon Song by Have Fun Teaching