## This python article has the main purpose to show you, how to calculate the area when the user input radius of the circle or find the Area of a circle. Also, we would love to share with you an algorithm to calculate the area based on a given radius of circle.

**First of all, you should know what is area of circle and also, find the area of circle formula.**

### What is area of circle?

The **area** of a **circle** is the number of square units inside that **circle**. If each square in the **circle** to the left has an **area** of 1 cm^{2}, you could count the total number of squares to get the **area** of this **circle**.

### What is area of circle formula?

The area of a circle can be found by multiplying pi ( π = 3.14) by the square of the radius. e.g. If a circle has a radius of 5, its area is **3.14*5*5=78.53**.

### Algorithm to find the Area of a circle in python

- Import math module in python program.
- Take input number from user.
- Calculate
**area**of the**circle**with a given radius by using formula**pi * r**2.** - Print result.

**Write a python program which accept the radius of a circle from the user and compute the area.**

# import math module from math import pi # take input from user r = float(input ("Input the radius of the circle : ")) # compute the area from radius of a circle given by user calculateArea = str(pi * r**2); #print result print ("The area of the circle with radius " + str(r) + " is: " + calculateArea)

After executing the program, the output will be:

Input the radius of the circle : 2 The area of the circle with radius 2.0 is: 12.566370614359172

Thanks for helping