Python Program to Find Area of Triangle

You can find the area of a triangle in Python by using the formula area = 0.5 * base * height, where base and height are the triangle's base and height values.

Examples

Inputbase = 4, height = 3

OutputArea of the triangle is 6.0

Inputbase = 10, height = 5

OutputArea of the triangle is 25.0

Inputbase = 0, height = 7

OutputArea of the triangle is 0.0

How to Think About It

To find the area of a triangle, you need to know its base length and height. The area is half the product of the base and height, so multiply base and height, then divide by 2.

Algorithm

1

Get the base length from the user

2

Get the height from the user

3

Calculate area by multiplying base and height, then dividing by 2

4

Display the calculated area

Code

python

base = float(input('Enter the base of the triangle: '))
height = float(input('Enter the height of the triangle: '))
area = 0.5 * base * height
print('Area of the triangle is', area)

Output

Enter the base of the triangle: 4
Enter the height of the triangle: 3
Area of the triangle is 6.0

Dry Run

Let's trace the example where base = 4 and height = 3 through the code

1

Input base

User enters 4, so base = 4.0

2

Input height

User enters 3, so height = 3.0

3

Calculate area

area = 0.5 * 4.0 * 3.0 = 6.0

4

Print result

Output: Area of the triangle is 6.0

Step	Variable	Value
1	base	4.0
2	height	3.0
3	area	6.0

Why This Works

Step 1: Getting inputs

We use input() to get base and height from the user and convert them to float numbers for calculation.

Step 2: Calculating area

The formula 0.5 * base * height calculates the triangle's area by multiplying base and height, then taking half.

Step 3: Displaying output

We print the result with a clear message so the user understands the output.

Alternative Approaches

Using Heron's formula with three sides

python

import math
side1 = float(input('Enter side 1: '))
side2 = float(input('Enter side 2: '))
side3 = float(input('Enter side 3: '))

s = (side1 + side2 + side3) / 2
area = math.sqrt(s * (s - side1) * (s - side2) * (s - side3))
print('Area of the triangle is', area)

This method calculates area when you know all three sides, but it is more complex than base-height method.

Using a function to reuse code

python

def triangle_area(base, height):
    return 0.5 * base * height

b = float(input('Base: '))
h = float(input('Height: '))
print('Area of the triangle is', triangle_area(b, h))

This approach organizes code better and allows easy reuse for multiple calculations.

Complexity: O(1) time, O(1) space

Time Complexity

The calculation uses a fixed number of arithmetic operations, so it runs in constant time.

Space Complexity

Only a few variables are used, so space usage is constant.

Which Approach is Fastest?

The base-height formula is simplest and fastest; Heron's formula is slower due to square root and more inputs.

Approach	Time	Space	Best For
Base and Height Formula	O(1)	O(1)	Simple known base and height
Heron's Formula	O(1)	O(1)	Known three sides, no height
Function Wrapper	O(1)	O(1)	Reusable code for multiple calculations