Virginia SOL Math / Grade 3 / Measurement & Geometry
Area & Perimeter
What you'll learn
- Measure area by counting square units
- Find the perimeter by adding side lengths
- Solve problems in context involving area and perimeter
Words to know
- Area —
- the number of square units that cover a shape
- Perimeter —
- the distance all the way around a shape
- Square unit —
- one unit-by-unit square used to measure area
- Side length —
- how long one side of a shape is
Why it matters Area tells us how much space a floor or garden covers; perimeter tells us how much fence or border we need around it.
Worked examples
Model ItI do
Find the area and perimeter of this rectangle.
Area: count the squares, 5 × 3 = 15 square units. Perimeter: add the sides, 5 + 3 + 5 + 3 = 16 units.
Try It TogetherWe do
A square rug has sides of 4 feet. What is its perimeter?
A square has 4 equal sides: 4 + 4 + 4 + 4 = 16 feet. (Or 4 × 4 = 16 feet.)
Now YouYou do
A rectangle is 6 units long and 2 units wide. Find its area.
Multiply length by width, or count squares. Check your answer in the back.
Practice
Mastered 0 of 11
Warm-up
Ease in with the basics.
1.Find the area of a rectangle that is 5 units by 2 units.
2.Find the perimeter of a rectangle 6 units by 3 units.
3.Which measures the space that covers a shape: area or perimeter?
On Level
The core Quick Check from the book.
1.Find the area of a rectangle that is 4 units by 3 units.
2.Find the perimeter of a rectangle 7 units by 2 units.
3.A square has sides of 5 cm. What is its area?
4.Which measures the distance around a shape: area or perimeter?
5.A garden is 8 ft by 5 ft. How much fence goes around it?
Challenge
Stretch your thinking.
1.A square garden has sides of 9 feet. Find its area and its perimeter.
2.A rectangle has an area of 24 square units and a length of 6 units. What is its width?
3.A rectangular rug is 8 feet long and 4 feet wide. How much braid is needed to go all the way around it?