The perimeter is the edge all around a two-dimensional shape; it is also the distance all the way around the shape.
Here is a picture of a one square-inch tile.
Each side of this tile is one inch long.
The perimeter of the tile is 4 inches.
The area of the tile is one square inch.
Area is the amount of surface that is needed to cover something. The size of an object or shape is often measured by counting the number of unit squares that can be placed on top of the shape to cover it. This is called the area of the object.
A grid of square-inch tiles has been drawn on the diagram of the fountain. You can use it to measure the distance the ants walked to travel the perimeter of the fountain. The grid of tiles can also help you measure the square inches needed to cover the area of the fountain.
- Find the perimeter of the fountain.
- Find the area of the fountain.
- Find the area of the fountain that is covered by water.
- Find the area of the fountain that is not covered by water.
Use the Perimeter-Area Puzzles pages in the Student Activity Book to practice measuring the perimeter and area of different shapes.
Check-In: Questions 5–6
The ants of Antopolis want to build a playground with an area of 8 square inches. They have ordered enough material to build a 14-inch fence around it.
- Draw a design for a playground for the ants which has an area of 8 square inches and a perimeter of 14 inches. (They want the young ants to be able to walk from one part of the playground to any other part without going outside the perimeter.)
- Write a paragraph that explains how you chose your playground design. Use expectations on the Math Practices page to help you write your paragraph. Look in your Student Guide Reference section.
Continue to practice finding area and perimeter using the Measuring Area and Perimeter pages in the Student Activity Book.