🚀 Day 21/150 – Perimeter of a Rectangle in Python

Understanding how to calculate the perimeter of a rectangle is one of the simplest yet important concepts in programming. It helps you build a strong foundation in working with formulas, user input, and functions in Python.

The formula for the perimeter of a rectangle is:

$$\text{Perimeter} = 2 \times (length + width)$$

Let’s explore different ways to implement this in Python 👇

---

🔹 Method 1 – Direct Calculation

This is the simplest way where we directly assign values to length and width.

length = 10
width = 5

perimeter = 2 * (length + width)

print("Perimeter of rectangle:", perimeter)

🧠 Explanation:

• We define length and width.
• Apply the formula: 2 * (length + width)
• Print the result.

👉 Best for: Beginners and quick calculations.

---

🔹 Method 2 – Taking User Input

This method makes your program interactive by allowing users to enter values.

length = float(input("Enter length: "))
width = float(input("Enter width: "))

perimeter = 2 * (length + width)

print("Perimeter of rectangle:", perimeter)

🧠 Explanation:

• input() takes user input.
• float() converts input into decimal numbers.
• Same formula is applied afterward.

👉 Best for: Real-world applications where input varies.

---

🔹 Method 3 – Using a Function

Functions make your code reusable and clean.

def find_perimeter(l, w):
    return 2 * (l + w)

print(find_perimeter(10, 5))

🧠 Explanation:

• def is used to define a function.
• l and w are parameters.
• return sends back the calculated value.

👉 Best for: Writing modular and reusable code.

---

⚡ Key Takeaways

• The formula is simple: 2 × (length + width)
• Use direct values for quick tasks.
• Use input() for interactive programs.
• Use functions for clean and reusable code.