Find the Area of a Triangle In Python

In this post, we will learn how to write a program to find the area of a triangle in python with a detailed explanation but before writing a program it is important to know the formula for finding the area of a triangle.

So let’s see the formula for finding the area of a triangle…

Table of Contents hide

1 Formula for Area of a Triangle

1.1 Source Code

1.2 Output

2 Find the Area of a Triangle with a base and height

2.1 Source Code

2.2 Output

Formula for Area of a Triangle

The formula is: area = sqrt(s * (s-a) * (s-b) * (s-c))

where “s” is the semi-perimeter of the triangle.
“a“, “b“ and “c“ are the lengths of the triangle’s sides.

Formula to find semi-perimeter of the triangle is as follow:

s = (a + b + c) / 2

From the above formula, we understood how to implement a python program to calculate the area of a triangle but before writing a program few programming concepts you have to know:

Source Code

import math

a = float(input("Enter length of side a : "))
b = float(input("Enter length of side b : "))
c = float(input("Enter length of side c : "))

s = (a+b+c)/2
area = math.sqrt(s*(s-a)*(s-b)*(s-c))

print(f"Area of a Triangle is {area:.2f}")

Output

Enter length of side a : 3
Enter length of side b : 4
Enter length of side c : 5
Area of a Triangle is 6.00

We can also find an area of a triangle using the length of its height and base.

Find the Area of a Triangle with a base and height

The formula is: area = (1/2) * base * height

let’s write a program using the height and base of the triangle and see the output.

Source Code

base = float(input("Enter the base of the triangle: "))
height = float(input("Enter the height of the triangle: "))

if base > 0 and height > 0:
    area = (1/2) * base * height
    print(f"The area of the triangle is: {area:.2f}")
else:
    print("Please enter positive numbers for base and height.")