Grade 4 · Math · Lesson 27

Measure Area and Perimeter

Perimeter and area are two ways to measure a shape. Perimeter tells us the total distance around the outside of a shape. Area tells us how much space is inside a shape. Both measurements are used every day — when fencing a garden, tiling a floor, or planning a room layout. In the US we measure small things in inches and large things in feet; the rest of the world (and science) uses centimeters and meters. Both systems work the same way — only the unit label changes.

What this lesson teaches

1Calculate the perimeter of rectangles and polygons in both customary (in, ft) and metric (cm, m) units
2Calculate the area of rectangles using length × width and report it in square inches, square feet, square centimeters, or square meters
3Apply area and perimeter formulas to real-life problems in both US customary and metric units

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