What is Perimeter of a Rectangle?

S1-SA3-0237

Grade Level:

Class 2

All STEM domains, Finance, Economics, Data Science, AI, Physics, Chemistry

Definition

What is it?

The perimeter of a rectangle is the total distance around its outer edge. Imagine walking along all four sides of a rectangular park; the total distance you walk is its perimeter.

Simple Example

Quick Example

Your school playground is a rectangle. If you walk along the boundary from one corner, cover all its sides, and come back to your starting point, the total distance you covered is the perimeter of the playground.

Worked Example

Step-by-Step

Let's find the perimeter of a rectangular chai stall. Its length is 5 meters and its width is 3 meters.
---Step 1: Identify the length and width. Length = 5 meters, Width = 3 meters.
---Step 2: Remember that a rectangle has two lengths and two widths. So, the sides are 5m, 3m, 5m, and 3m.
---Step 3: Add all the side lengths together: 5 + 3 + 5 + 3
---Step 4: Calculate the sum: 5 + 3 = 8; 8 + 5 = 13; 13 + 3 = 16.
---Step 5: The total distance around the chai stall is 16 meters.
Answer: The perimeter of the rectangular chai stall is 16 meters.

Why It Matters

Understanding perimeter helps architects design buildings, engineers plan roads, and even tailors measure fabric for clothes. It's crucial for anyone who needs to calculate the boundary or fencing for an area, like a farmer fencing their field or a construction worker marking a plot.

Common Mistakes

MISTAKE: Adding only the length and width. | CORRECTION: Remember a rectangle has four sides, so you need to add all four sides (two lengths and two widths).

MISTAKE: Confusing perimeter with area. | CORRECTION: Perimeter is the distance AROUND the shape, while area is the space INSIDE the shape.

MISTAKE: Forgetting to include units in the final answer. | CORRECTION: Always write the unit (like meters, centimeters, kilometers) with your answer, as it tells us what we are measuring.

Practice Questions

Try It Yourself

QUESTION: A rectangular cricket pitch is 22 meters long and 10 meters wide. What is its perimeter? | ANSWER: 64 meters

QUESTION: Your mobile phone screen is a rectangle. If its length is 15 cm and its width is 7 cm, what is the perimeter of the screen? | ANSWER: 44 cm

QUESTION: A rectangular school garden has a length of 20 meters. If its width is half of its length, what is the perimeter of the garden? | ANSWER: 60 meters

MCQ

Quick Quiz

What is the perimeter of a rectangular table with a length of 120 cm and a width of 60 cm?

180 cm

360 cm

7200 sq cm

240 cm

The Correct Answer Is:

To find the perimeter, you add all four sides: 120 cm + 60 cm + 120 cm + 60 cm = 360 cm. Options A and D are incorrect as they don't add all sides. Option C is area, not perimeter.

Real World Connection

In the Real World

When a carpenter makes a rectangular photo frame, they need to calculate the perimeter to know how much wood strip or decorative border is needed. Similarly, when a tailor stitches a border around a rectangular saree, they use the concept of perimeter to measure the length of the border material required.

Key Vocabulary

Key Terms

PERIMETER: The total distance around the outside of a shape | RECTANGLE: A four-sided shape with opposite sides equal and all corners square (90 degrees) | LENGTH: The longer side of a rectangle | WIDTH: The shorter side of a rectangle | UNIT: A standard measure like meters, centimeters, or kilometers

What's Next

What to Learn Next

Great job learning about the perimeter of a rectangle! Next, you can explore how to find the perimeter of other shapes like squares and triangles. This will help you understand how to measure boundaries for all sorts of everyday objects.