When you gaze at the floor, a wall, or even a garden, you see particular shapes. All these shapes have an area and a perimeter. In mathematics, area and perimeter provides a method of measuring within a given space.
Area explains how much surface is covered, whereas perimeter measures how long the boundary is. Regardless if you are laying down tiles, fencing a plot, or wrapping a gift, knowing how to calculate the perimeter and area will help a lot. The aim of this blog is to help you understand the concepts of area and perimeter, their calculations and formulas, and some practical examples that will make comprehension easier.
Table of Contents
Area refers to the surface covered by a shape or figure. It is measured in square units such as square centimetres (cm²), square meters (m²), etc.
Example: If you have a square tile that is 1 meter long on each side, the area it covers is 1 square meter.
Perimeter is the distance around a shape. It is measured in units of length such as meters (m), centimetres (cm), inches, etc.
Example: If a rectangle has a length of 5 meters and a width of 2 meters, then the perimeter is the total distance around it.
Understanding area and perimeter is useful in many daily activities:
Measuring land for construction
Buying tiles or paint
Installing fences or walls
Designing floor plans
Making crafts or wrapping gifts
Depending on the size and object, different units are used:
Quantity |
Unit Example |
Area |
cm², m², km² |
Perimeter |
cm, m, km |
Make sure the units for all sides are the same before applying any formula.
Let’s explore the area and perimeter formula for common shapes:
Area = side × side
Perimeter = 4 × side
Area = length × width
Perimeter = 2 × (length + width)
Area = ½ × base × height
Perimeter = sum of all sides
Area = π × radius²
Perimeter (Circumference) = 2 × π × radius
Area = base × height
Perimeter = 2 × (base + side)
Area = ½ × (sum of parallel sides) × height
Perimeter = the sum of all sides
These area and perimeter formulas are widely used in both academic and practical situations.
Side = 5 cm
Area = 5 × 5 = 25 cm²
Perimeter = 4 × 5 = 20 cm
Length = 8 m, Width = 3 m
Area = 8 × 3 = 24 m²
Perimeter = 2 × (8 + 3) = 22 m
Base = 10 cm, Height = 5 cm
Sides = 10 cm, 7 cm, 6 cm
Area = ½ × 10 × 5 = 25 cm²
Perimeter = 10 + 7 + 6 = 23 cm
Radius = 7 cm
Area = π × 7² = 154 cm² (approx)
Perimeter = 2 × π × 7 = 44 cm (approx)
These examples show how useful area of perimeter formula can be.
Fencing a Garden: You need to calculate the perimeter to buy the correct length of fence.
Painting a Wall: Calculate the area to know how much paint to buy.
Designing a Playground: Determine area to plan space for slides and swings.
Buying Carpet: Know the area of the floor to purchase the right size.
These real-world uses show the value of understanding the formula of area and perimeter.
Q1. A rectangular floor is 10 m long and 8 m wide. Find the area and perimeter.
Area = 10 × 8 = 80 m²
Perimeter = 2 × (10 + 8) = 36 m
Q2. A square playground has a side of 20 m. How much fencing is needed?
Perimeter = 4 × 20 = 80 m
Q3. A circular pond has a radius of 14 m. What is the area?
Area = π × 14² = 615.75 m² (approx)
Word problems give practice applying the area and perimeter formula in real scenarios.
Mixing up area and perimeter (area is space inside, perimeter is the boundary)
Using wrong units (always convert to the same unit before solving)
Forgetting π ≈ 3.14 in circular calculations
Forgetting to square the radius when calculating area of a circle
Using height instead of side in square formulas
Careful reading and double-checking can prevent errors when solving math area and perimeter questions.
Find the area and perimeter of a rectangle with length 15 cm and width 4 cm.
A square has a side of 12 m. What is its area and perimeter?
A triangle has a base of 10 cm and height of 6 cm. What is the area?
Find the perimeter of a triangle with sides 7 cm, 8 cm, and 9 cm.
A circle has a radius of 5 cm. Find its area and circumference.
Practice these to get more comfortable with the area and perimeter formula.
Area and perimeter are two important concepts. They enable us to solve practical problems, plan designs, and measure different shapes with consideration to area and perimeter. It is equally important to understand how to use the formulae for circles, triangles, rectangles and even squares. The knowledge is valuable in our day-to-day life, and not just during examinations. Be it during budgeting as an adult or in planning during school, be ready to tackle geometry and many other measurement-related problems with ease.
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The formula for area depends on the shape. For a rectangle, it's:
Area = length × breadth
The formula for perimeter is the total distance around the shape. For a rectangle:
Perimeter = 2 × (length + breadth)
To find the perimeter, add the lengths of all sides of a shape.
To find the area, multiply the relevant dimensions (like length and width for rectangles). Always check which shape you're working with to use the correct formula.
To calculate the area, use the shape-specific formula. For example:
Rectangle: length × breadth
Triangle: ½ × base × height
Square: side × side
First, identify the shape and its dimensions. Then:
Use the right area formula to find the space inside.
Use the correct perimeter formula to find the length around it.
Always write units like cm² for area and cm for perimeter.
The perimeter formula depends on the shape. For example:
Rectangle: 2 × (length + breadth)
Square: 4 × side
Triangle: Add all three sides
Explore more math topics like this at your own pace and become confident in problem-solving!