TypeScript: Calculate the Area of a Circle

1. Introduction

Calculating the area of geometric shapes is a fundamental task in mathematics and programming. The area of a circle can be found using the formula π * r^2, where r is the radius of the circle. In this guide, we'll implement a TypeScript function to compute the area of a circle given its radius.

2. Program Overview

We'll be creating a function named calculateCircleArea that will take the radius of the circle as an argument. The function will return the computed area of the circle using the aforementioned formula.

3. Code Program

// Function to calculate the area of a circle given its radius
function calculateCircleArea(radius: number): number {
    // Using the Math.PI constant to get the value of π
    return Math.PI * radius * radius;
}

// Testing the function
const circleRadius: number = 5;
console.log(`The area of a circle with radius ${circleRadius} is: ${calculateCircleArea(circleRadius).toFixed(2)}`);

Output:

The area of a circle with radius 5 is: 78.54

4. Step By Step Explanation

1. We define a function named calculateCircleArea that accepts the radius of a circle as its parameter.

2. Inside the function, we use the Math.PI constant to get the value of π (Pi).

3. We compute the area of the circle using the formula π * r^2 and return the result.

4. For testing purposes, we use a circle with a radius of 5 units.

5. When invoking the function with a radius of 5, it calculates and outputs the area as 78.54 square units (rounded to two decimal places).