Calculate Area of Triangle in JavaScript

In this post we are going to write a JavaScript program to find the “Area of Triangle”.

Here is the complete JavaScript program to find the “Area of Triangle”:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Area of Traingle - Simple JavaScript Example</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- Load Bootstrap library for better UI look & feel -->
    <link rel="stylesheet" type="text/css" media="screen" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" />
    <script>
      function findAreaOfTriangle(){
        var RecLen, RecWid, Area;
        RecLen = document.getElementById("rec_len").value;
        RecWid = document.getElementById("rec_wid").value;
        Area = RecLen * RecWid;
        document.getElementById("result").value = Area;
      }
    </script>
</head>
<body>
  <div class="container">
    <br />
      <h2>JavaScript to find Area of Square - Demo by Theonlytutorials.com</h2>
    <br />
    <div class="form-group">
      <label for="rec_len">Enter Rectangle Length:</label>
      <input type="text" class="form-control" id="rec_len" >
    </div>
    <div class="form-group">
      <label for="rec_wid">Enter Rectangle Width:</label>
      <input type="text" class="form-control req" id="rec_wid" >
    </div>
    <div class="form-group">
      <label for="result">Result:</label>
      <input type="text" class="form-control req" id="result" readonly >
    </div>
    <button type="submit" class="btn btn-default" onclick="findAreaOfTriangle()">Submit</button>
  </div>
</body>
</html>

You can also see the demo of the above script here: