4th Grade Area and Perimeter of Rectangles Lesson (Free PDF)
This area perimeter lesson for 4th Grade covers area and perimeter of rectangles (Common Core 4.MD.A.3), with a free PDF to print.
Area is the number of unit squares that cover a flat shape, and perimeter is the distance around it. For a rectangle, area = length × width and perimeter = 2 × length + 2 × width. A rectangle 8 feet long and 3 feet wide has an area of 24 square feet and a perimeter of 22 feet.
Grade 4 · Common Core State Standards: 4.MD.A.3
Key facts in this area perimeter lesson
- Area of a rectangle = length × width, measured in square units.
- Perimeter of a rectangle = 2 × length + 2 × width, measured in plain units.
- A square is a rectangle whose four sides are equal.
- If you know the area and one side, divide to find the other side.
- Area tells how much to cover; perimeter tells how far around.
What is the area of a rectangle?
Area tells how much flat space a shape covers. We count unit squares, like floor tiles. This rectangle has 6 squares in every row and 4 rows, so it has 24 squares.
\(A = l \times w\) where l is the length and w is the width. Area is measured in square units, such as square feet (sq ft) or square inches (sq in).
What is the perimeter of a rectangle?
Perimeter is the distance around the outside edge. Imagine walking along a fence. A rectangle has two long sides and two short sides, so add them all.
\(P = 2 \times l + 2 \times w\) or \(P = 2 \times (l + w)\). Perimeter is measured in plain units, such as feet or inches.
How do you find a missing side of a rectangle?
Area is length times width, so use division to undo it. If a rectangle has an area of 48 square feet and a length of 8 feet, then the width is \(48 \div 8 = 6\) feet.
How do you solve an area or perimeter word problem?
First decide what the question needs. A fence, a border, or a ribbon around something means perimeter. Carpet, paint, or grass covering something means area.
Example. Maya’s garden is 9 ft long and 5 ft wide. How much fence goes around it, and how much soil covers it?
- Fence is around the edge, so find the perimeter: \(2 \times 9 + 2 \times 5 = 18 + 10 = 28\) ft.
- Soil covers the garden, so find the area: \(9 \times 5 = 45\) square feet.
- Write the units: 28 ft of fence and 45 sq ft of soil.
Area perimeter lesson: questions and answers
What is the difference between area and perimeter?
Perimeter is the distance around a shape, so you add the side lengths. Area is the amount of space inside a shape, so you multiply length by width.
Why is area measured in square units?
Area counts squares that fit inside a shape. A square foot is a square that is 1 foot on each side, so the area of a floor is written in square feet.
How do you find the perimeter of a square?
A square has four equal sides, so multiply one side by 4. A square with sides of 6 inches has a perimeter of 4 × 6 = 24 inches.
How do you find a missing width when you know the perimeter?
Subtract the two known lengths from the perimeter, then divide by 2. If P = 30 in and the length is 9 in, then 30 – 18 = 12 and 12 ÷ 2 = 6 in.
Can two rectangles have the same perimeter but different areas?
Yes. A 7 ft by 3 ft rectangle and a 5 ft by 5 ft rectangle both have a perimeter of 20 ft, but their areas are 21 sq ft and 25 sq ft.
How to use this area perimeter lesson
Read the definitions first, then follow the worked method line by line and redo the example on paper without looking. When every step makes sense, move on to the worksheet, then check yourself with the quiz.
Download the area perimeter lesson as a PDF with the button below and keep it with your notes.
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