Use js to quickly find the area of a triangle-JS Tutorial-php.cn

Home

Web Front-end

JS Tutorial

Use js to quickly find the area of a triangle

藏色散人

Aug 06, 2021 pm 06:04 PM

Everyone should know the formula for the area of a triangle, that is, the area is equal to one-half times the base times the height. Haha, it doesn’t matter if you forget. This article will introduce to you how to calculate the area of a triangle using js.

First of all, let me give you a brief introduction to the triangle area formula:

The triangle area formula refers to using a formula to calculate the area of a triangle, three line segments in the same plane and not on the same straight line The closed figure formed by connecting end to end is called a triangle, and its symbol is △.

As shown below:

Use js to quickly find the area of a triangle

So after briefly understanding the triangle area formula, let me ask you a question: "Please write a JavaScript function to calculate The area of a triangle whose three sides have lengths 4, 5, and 6”.

I don’t know if you have any calculation ideas~

The following is the method I gave:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<script>
    var side1 = 4;
    var side2 = 5;
    var side3 = 6;
    var s = (side1 + side2 + side3)/2;
    var area =  Math.sqrt(s*((s-side1)*(s-side2)*(s-side3)));
    console.log(area);
</script>
</body>
</html>

The calculation result is:

9.921567416492215

In fact, this is a Math problem!

However, one knowledge point that everyone needs to master is Heron's formula. Heron's formula is also translated as Heron's formula, Hailong formula, Hero's formula, and Heron-Qin Jiushao formula; it is calculated directly by using the side lengths of the three sides of a triangle. The formula for the area of a triangle; the expression is: S=√p(p-a)(p-b)(p-c).

The popular explanation is:

It is known that the three sides are a, b, and c. The side lengths of our example here are 4, 5, and 6 respectively;

Let p= (a b c)/2, that is, the "(side1 side2 side3)/2"

area in the code is S=√[p(p-a)(p-b)(p-c)], It is "Math.sqrt(s*((s-side1)*(s-side2)*(s-side3)));".

You need to know a function here, which is the Math.sqrt() function, which is used to return the square root of a number;

→Note: Since sqrt is a static method of Math , so it should be used like this: Math.sqrt(), not as a method of the Math instance you created.

Finally, I would like to recommend "JavaScript Basics Tutorial" ~ Welcome everyone to learn ~

The above is the detailed content of Use js to quickly find the area of a triangle. For more information, please follow other related articles on the PHP Chinese website!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Understanding the JavaScript Engine: Implementation DetailsApr 17, 2025 am 12:05 AM

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AM

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AM

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.

From C/C to JavaScript: How It All WorksApr 14, 2025 am 12:05 AM

The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.

JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AM

Different JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.

Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AM

JavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.

Building a Multi-Tenant SaaS Application with Next.js (Backend Integration)Apr 11, 2025 am 08:23 AM

I built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing

How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration)Apr 11, 2025 am 08:22 AM

This article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base

See all articles