JavaScript | Finding a missing angle

First of all, don't be an idiot, put this in a directory where bootstrap is available, if you don't know how to, then enjoy a very ugly converter, apart from that, this code is bloody great (probably not, but it is, deal with it)
 <html>
 <head>
 <link href="css/bootstrap.css" rel="stylesheet">
 </head>
 <body>

  <div class='col-lg-3'>
    <div class='well'>

<h2>&nbsp;&nbsp;Find a missing angle</h2>
  <input class='form-control' type='text' id='q' placeholder=' opposite / adjacent'> <br>
    <input class='form-control' type='text' id='e' placeholder=' adjacent / hypotenuse'>  <br>
<br>
<p> sin <sup> -1 </sup>
<input class='btn btn-success' type='button' onClick='aSin()' value='sin'> <input class='btn btn-success' type='button' onClick='aSind()' value='Round'>

<br>
<p> cos <sup> -1 </sup> 
<input class='btn btn-info' type='button' onClick='aCos()' value='cos'> <input class='btn btn-info' type='button' onClick='aCosd()' value='Round'>

<br>
<p> tan <sup> -1 </sup> 
<input class='btn btn-warning' type='button' onClick='aTan()' value='tan'> <input class='btn btn-warning' type='button' onClick='aTand()' value='Round'>
<p id='w'> </p>
  </div>

<script>


function toRadians (angle) {
  return angle * (Math.PI / 180);
}  
  
  function aSin() {
    var a = document.getElementById('q').value;
    var c = document.getElementById('e').value;
    var z = a / c
    var b = document.getElementById('w').innerHTML =  Math.asin(z) * (180 / Math.PI);
  }
  
  function aSind() {
   var a = document.getElementById('q').value;
    var c = document.getElementById('e').value;
    var z = a / c 
    var t = Math.asin(z) * (180 / Math.PI)
    var b = document.getElementById('w').innerHTML =  Math.round(t) + '&#186;';
  }

  function aCos() {
    var a = document.getElementById('q').value;
    var c = document.getElementById('e').value;
    var z = a / c
    var b = document.getElementById('w').innerHTML =  Math.acos(z) * (180 / Math.PI);
  }
  
  function aCosd() {
   var a = document.getElementById('q').value;
    var c = document.getElementById('e').value;
    var z = a / c 
    var t = Math.acos(z) * (180 / Math.PI)
    var b = document.getElementById('w').innerHTML =  Math.round(t) + '&#186;';
  }
  
  function aTan() {
    var a = document.getElementById('q').value;
    var c = document.getElementById('e').value;
    var z = a / c
    var b = document.getElementById('w').innerHTML =  Math.atan(z) * (180 / Math.PI);
  }
  
  function aTand() {
   var a = document.getElementById('q').value;
    var c = document.getElementById('e').value;
    var z = a / c 
    var t = Math.atan(z) * (180 / Math.PI)
    var b = document.getElementById('w').innerHTML =  Math.round(t) + '&#186;';
  }
  
  
</script>
</body>
</html>