Bash Script to Find Area of Triangle with Input and Output

Use a Bash script that reads base and height, then calculates area with area=$(echo "scale=2; 0.5 * $base * $height" | bc) and prints the result.

Examples

Inputbase=10, height=5

OutputArea of the triangle is 25.00

Inputbase=3, height=4

OutputArea of the triangle is 6.00

Inputbase=0, height=10

OutputArea of the triangle is 0.00

How to Think About It

To find the area of a triangle, you multiply the base by the height and then divide by 2. In Bash, since it does not support floating-point math directly, you use the bc command to perform the calculation.

Algorithm

1

Get the base value from the user

2

Get the height value from the user

3

Calculate the area using the formula (0.5 * base * height)

4

Print the calculated area

Code

bash

#!/bin/bash
read -p "Enter base of the triangle: " base
read -p "Enter height of the triangle: " height
area=$(echo "scale=2; 0.5 * $base * $height" | bc)
echo "Area of the triangle is $area"

Output

Enter base of the triangle: 10
Enter height of the triangle: 5
Area of the triangle is 25.00

Dry Run

Let's trace the example where base=10 and height=5 through the code

1

Read base

User inputs base=10

2

Read height

User inputs height=5

3

Calculate area

Calculate 0.5 * 10 * 5 = 25.00 using bc

Variable	Value
base	10
height	5
area	25.00

Why This Works

Step 1: Reading inputs

The script uses read to get base and height values from the user.

Step 2: Calculating area

Since Bash can't do floating math, it uses bc to compute 0.5 * base * height with two decimal places.

Step 3: Displaying result

The script prints the area with a clear message using echo.

Alternative Approaches

Using awk for calculation

bash

#!/bin/bash
read -p "Enter base: " base
read -p "Enter height: " height
area=$(awk "BEGIN {print 0.5 * $base * $height}")
echo "Area of the triangle is $area"

This uses awk for floating-point math instead of bc; simpler but requires awk installed.

Using integer math approximation

bash

#!/bin/bash
read -p "Enter base (integer): " base
read -p "Enter height (integer): " height
area=$((base * height / 2))
echo "Approximate area of the triangle is $area"

This uses integer math only, so no decimals; simpler but less precise.

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

Time Complexity

The script performs a fixed number of operations regardless of input size, so it runs in constant time O(1).

Space Complexity

It uses a few variables to store inputs and result, so space usage is constant O(1).

Which Approach is Fastest?

Using integer math is fastest but less accurate; bc and awk provide floating-point precision with minimal overhead.

Approach	Time	Space	Best For
Using bc	O(1)	O(1)	Accurate floating-point calculations
Using awk	O(1)	O(1)	Simple floating-point math without bc
Integer math	O(1)	O(1)	Fastest but only integer results