Perimeter of Square
A square has four equal sides. The perimeter of a square is the total distance around all four sides. Since all sides are equal, finding the perimeter is simple -- multiply one side by 4.
In Class 3, students learn the perimeter formula for a square and apply it to real-life problems like fencing, bordering, and measuring.
What is Perimeter of Square - Class 3 Maths (Geometry)?
The perimeter of a square is the sum of all four equal sides.
Perimeter of Square = 4 × Side
Perimeter of Square Formula
P = 4 × S
Where S = the length of one side of the square.
Solved Examples
Example 1: Basic Perimeter Calculation
Question: Find the perimeter of a square with side 7 cm.
Think:
- P = 4 × 7 = 28 cm
Answer: The perimeter is 28 cm.
Example 2: Fencing a Square Garden
Question: Ria's garden is a square with each side 9 m. How much fencing does she need?
Think:
- Fencing = perimeter
- P = 4 × 9 = 36 m
Answer: Ria needs 36 m of fencing.
Example 3: Ribbon Around a Square Card
Question: Priya puts ribbon around a square greeting card with side 15 cm. How much ribbon does she need?
Think:
- P = 4 × 15 = 60 cm
Answer: Priya needs 60 cm of ribbon.
Example 4: Finding Side from Perimeter
Question: A square has a perimeter of 48 cm. Find the length of one side.
Think:
- P = 4 × Side
- 48 = 4 × Side
- Side = 48 ÷ 4 = 12 cm
Answer: Each side is 12 cm.
Example 5: Perimeter of a Square Room
Question: Aman's room is square-shaped with each wall 4 m long. He wants to put a decorative border along the base of all walls. How long should the border be?
Think:
- P = 4 × 4 = 16 m
Answer: The border should be 16 m long.
Example 6: Cost of Wire Around a Square
Question: Dev needs wire to go around a square frame with side 20 cm. Wire costs ₹2 per cm. What is the total cost?
Think:
- P = 4 × 20 = 80 cm
- Cost = 80 × ₹2 = ₹160
Answer: The total cost is ₹160.
Example 7: Comparing Square and Rectangle Perimeters
Question: A square has side 5 cm. A rectangle has length 7 cm and breadth 3 cm. Which has a larger perimeter?
Think:
- Square: P = 4 × 5 = 20 cm
- Rectangle: P = 2 × (7 + 3) = 20 cm
Answer: Both have the same perimeter of 20 cm.
Example 8: Perimeter on a Grid
Question: A square is drawn on a 1-cm grid. It covers 5 squares along each side. What is its perimeter?
Think:
- Side = 5 cm
- P = 4 × 5 = 20 cm
Answer: The perimeter is 20 cm.
Example 9: Real-Life Problem - Cricket Pitch
Question: A square practice pitch has each side 10 m. Kavi runs around it 3 times. How far does he run?
Think:
- P = 4 × 10 = 40 m (one round)
- 3 rounds = 3 × 40 = 120 m
Answer: Kavi runs 120 m in total.
Key Points to Remember
- A square has 4 equal sides.
- Perimeter of a square = 4 × side.
- If the perimeter is known, side = perimeter ÷ 4.
- Perimeter is measured in the same unit as the side (cm, m, etc.).
- A square is a special rectangle, so 2 × (L + B) also works when L = B.
- Real-life uses: fencing, bordering, framing, running around a field.
Practice Problems
- Find the perimeter of a square with side 11 cm.
- A square park has each side 25 m. What is its perimeter?
- Aditi puts lace around a square handkerchief with side 20 cm. How much lace does she need?
- A square has a perimeter of 32 cm. What is the length of each side?
- Meera's square photo frame has a perimeter of 60 cm. Find the side length.
- Wire costs ₹3 per metre. What is the cost of wiring around a square plot with side 15 m?
- Rahul runs around a square field with side 30 m. He runs 2 rounds. How far does he run?
Frequently Asked Questions
Q1. What is the formula for the perimeter of a square?
Perimeter of a square = 4 multiplied by the length of one side. In short, P = 4 x S.
Q2. How do you find the side of a square from its perimeter?
Divide the perimeter by 4. For example, if the perimeter is 36 cm, the side = 36 divided by 4 = 9 cm.
Q3. Why is the perimeter of a square 4 times the side?
A square has 4 equal sides. Adding all four: S + S + S + S = 4 x S.
Q4. Is a square a special type of rectangle?
Yes. A square is a rectangle where the length equals the breadth. The rectangle formula 2 x (L + B) gives the same result as 4 x S when L = B = S.
Q5. Can a square and a rectangle have the same perimeter?
Yes. A square with side 6 cm has perimeter 24 cm. A rectangle with length 8 cm and breadth 4 cm also has perimeter 24 cm.
Q6. What unit is perimeter measured in?
Perimeter uses the same unit as the sides. If the side is in centimetres, the perimeter is in centimetres. If the side is in metres, the perimeter is in metres.
Q7. Where do we use perimeter of a square in real life?
Perimeter of a square is used for fencing square gardens, putting ribbon around square cards, building square frames, and measuring distances around square fields.
Q8. Is perimeter of square covered in NCERT Class 3?
Yes. The perimeter of a square is part of the Geometry chapter in NCERT Class 3 Maths. Students learn the formula and solve word problems.
