Courses/course Content/python/learn | AI Content & Learning

In this activity, we will build an Area Calculator that can compute the area of three different shapes — a square, a rectangle, and a circle — based on the user's choice.

Shapes and Their Area Formulas

A blue square with a label showing Area = side x side — Square: side²

A green rectangle with a label showing Area = length x width — Rectangle: l × w

An orange circle with a label showing Area = pi x radius squared — Circle: π × r²

Area Formulas

Shape	Formula	Variables
Square	Area = side × side	side
Rectangle	Area = length × width	length, width
Circle	Area = π × radius²	radius (use math.pi for π)

Writing the Script

# Area Calculator import math print("Area Calculator") print("1. Square") print("2. Rectangle") print("3. Circle") choice = int(input("Choose a shape (1/2/3): ")) if choice == 1: side = float(input("Enter the side length: ")) area = side ** 2 print("Area of the square: " + str(area)) elif choice == 2: length = float(input("Enter the length: ")) width = float(input("Enter the width: ")) area = length * width print("Area of the rectangle: " + str(area)) elif choice == 3: radius = float(input("Enter the radius: ")) area = math.pi * radius ** 2 print("Area of the circle: " + str(round(area, 2))) else: print("Invalid choice. Please enter 1, 2, or 3.")

Understanding the Code

Code Breakdown

Line	What it Does
import math	Imports the math module to access math.pi
choice = int(input(...))	Gets the user's shape choice as an integer
side ** 2	Calculates the square of the side length
math.pi	The value of π (approximately 3.14159)
round(area, 2)	Rounds the result to 2 decimal places

Testing the Program

Run with choice = 1, side = 5 → Area should be 25.0
Run with choice = 2, length = 6, width = 4 → Area should be 24.0
Run with choice = 3, radius = 7 → Area should be approximately 153.94

Python console showing three test runs of the area calculator — one for square, one for rectangle, and one for circle with correct results printed

Save your file with the name Area Calculator before moving on!