How to find the area of a triangle using JavaScript ?

We are using JavaScript to solve a simple geometry problem: finding the area of a triangle. In this article, we'll show you different ways to do it. Whether you're new to coding or want to understand JavaScript better, follow along as we figure out how to find the area of a triangle

Below are the approaches:

Approach 1: When height is known

When the height(h) and base(b) are known then we could use the Formula to find the Area of the Triangle:

area = (base * height) / 2

Example: Below is an example of the above-explained approach.

function triangleArea(base, height) {
  return 0.5 * base * height;
}

// Example usage
let baseLength = 10;
let heightLength = 5;
let area = triangleArea(baseLength, heightLength);
console.log(`The area of the triangle is: ${area}`);

The area of the triangle is: 25

Approach 2: When all sides are known

When all sides(s1, s2, s3) are known then we could use:

Formula to find the Area of the Triangle:

let s = (side1 + side2 + side3) / 2;
let area = Math.sqrt(s * ((s - side1) * (s - side2) * (s - side3)));

Example: This example shows the area of triangle using JavaScript.

function triangleArea(side1, side2, side3) {
  // Calculate the semi-perimeter
  let s = (side1 + side2 + side3) / 2;

  // Use Heron's Formula to find the area
  return Math.sqrt(s * (s - side1) * (s - side2) * (s - side3));
}

// Example usage
let side1Length = 3;
let side2Length = 4;
let side3Length = 5;
let area = triangleArea(side1Length, side2Length, side3Length);
console.log(`The area of the triangle is: ${area}`);

The area of the triangle is: 6