Calculating the Area of a Triangle Based on Side Lengths

The following example demonstrates how to calculate the area of a triangle using the lengths of its three sides provided by the user:

Example (Python 3.0+):

# -*- coding: UTF-8 -*-

# Input the lengths of the triangle's three sides
a = float(input('Enter the length of the first side: '))
b = float(input('Enter the length of the second side: '))
c = float(input('Enter the length of the third side: '))

# Calculate the semi-perimeter
s = (a + b + c) / 2

# Calculate the area using Heron's formula
area = (s * (s - a) * (s - b) * (s - c)) ** 0.5
print('The area of the triangle is %0.2f' % area)

When you run this code, the output will be:

Output:

$ python test.py
Enter the length of the first side: 5
Enter the length of the second side: 6
Enter the length of the third side: 7
The area of the triangle is 14.70

In this example, the program calculates the area of a triangle using Heron’s formula. The user inputs the lengths of the three sides, and the semi-perimeter is computed as $s = \frac{a + b + c}{2}$. The area is then calculated by taking the square root of $s(s - a)(s - b)(s - c)$.