Part of the series

Several example codes

~2 min read • Updated Oct 1, 2025

Program Overview

This Python program calculates the intersection point of two lines:
Line 1: y = ax + b
Line 2: y = rx + c
It reads the coefficients a, b, r, and c from the user and applies the following formulas:
x = (b - c) / (r - a)
y = r * x + c


Python Code:


# Read coefficients from user
a = float(input("Enter coefficient a (Line 1 slope): "))
b = float(input("Enter coefficient b (Line 1 intercept): "))
r = float(input("Enter coefficient r (Line 2 slope): "))
c = float(input("Enter coefficient c (Line 2 intercept): "))

# Check for parallel lines
if r == a:
    print("\n--- Result ---")
    print("The lines are parallel and do not intersect.")
else:
    # Calculate intersection point
    x = (b - c) / (r - a)
    y = r * x + c

    # Display result
    print("\n--- Intersection Point ---")
    print(f"x = {x:.4f}")
    print(f"y = {y:.4f}")

Sample Output:


Enter coefficient a (Line 1 slope): 2  
Enter coefficient b (Line 1 intercept): 3  
Enter coefficient r (Line 2 slope): -1  
Enter coefficient c (Line 2 intercept): 4  

--- Intersection Point ---
x = -0.3333  
y = 4.3333

Step-by-Step Explanation:

- The user enters the slope and intercept for both lines
- If the slopes are equal, the lines are parallel and do not intersect
- Otherwise, the program calculates the x-coordinate using (b - c) / (r - a)
- Then it calculates y using r * x + c
- The result is printed with four decimal places


Written & researched by Dr. Shahin Siami