# Python: Test if circumference of two circles intersect or overlap

## Python Basic - 1: Exercise-45 with Solution

There are two circles C1 with radius r1, central coordinate (x1, y1) and C2 with radius r2 and central coordinate (x2, y2)

Write a Python program to test the followings -- "C2 is in C1" if C2 is in C1
- "C1 is in C2" if C1 is in C2
- "Circumference of C1 and C2 intersect" if circumference of C1 and C2 intersect
- "C1 and C2 do not overlap" if C1 and C2 do not overlap and
- "Circumference of C1 and C2 will touch" if C1 and C2 touch

**Input:**

Input numbers (real numbers) are separated by a space.

**Visual Presentation:**

**Sample Solution**:

**Python Code:**

```
# Import the math module
import math
# Prompt the user to input x1, y1, r1, x2, y2, r2
print("Input x1, y1, r1, x2, y2, r2:")
# Take user input and convert it to floating-point numbers
x1, y1, r1, x2, y2, r2 = [float(i) for i in input().split()]
# Calculate the distance between the centers of the two circles
d = math.sqrt((x1 - x2)**2 + (y1 - y2)**2)
# Check and print the relationship between the two circles based on their radii and distance
if d <= r1 - r2:
print("C2 is in C1")
elif d <= r2 - r1:
print("C1 is in C2")
elif d < r1 + r2:
print("Circumference of C1 and C2 intersect")
elif d == r1 + r2:
print("Circumference of C1 and C2 will touch")
else:
print("C1 and C2 do not overlap")
```

Sample Output:

Input x1, y1, r1, x2, y2, r2: 5 4 2 3 9 2 C1 and C2 do not overlap

Input x1, y1, r1, x2, y2, r2: 5 4 3 5 10 3 Circumference of C1 and C2 will touch

Input x1, y1, r1, x2, y2, r2: 6 4 3 10 4 2 Circumference of C1 and C2 intersect

Input x1, y1, r1, x2, y2, r2: 5 4 3 5 4 2 C2 is in C1

Input x1, y1, r1, x2, y2, r2: 5 4 2 5 4 3 C1 is in C2

**Explanation:**

Here is a breakdown of the above Python code:

- The code imports the "math" module.
- It prompts the user to input the coordinates and radii of two circles (x1, y1, r1, x2, y2, r2).
- It calculates the distance (d) between the centers of the two circles using the distance formula.
- The code checks the relationship between two circles based on their radii and distance.
- It prints the appropriate message indicating the relationship between the circles.

**Flowchart:**

**Python Code Editor:**

**Have another way to solve this solution? Contribute your code (and comments) through Disqus.**

**Previous:** Write a Python program to find the maximum sum of a contiguous subsequence from a given sequence of numbers a1, a2, a3, ... an. A subsequence of one element is also a continuous subsequence.

**Next:** Write a Python program to that reads a date (from 2016/1/1 to 2016/12/31) and prints the day of the date. Jan. 1, 2016, is Friday. Note that 2016 is a leap year.

**What is the difficulty level of this exercise?**

Test your Programming skills with w3resource's quiz.

**Weekly Trends and Language Statistics**- Weekly Trends and Language Statistics