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JavaScript JavaScript Foundations Numbers The Math Object

Posted by Ira Salem
Ira Salem
10,331 Points

JavaScript

I'm supposed to be creating a variable called "circumference" and finding the circumference using the Math.Pi object and the variable called "diameter". What am I not doing right here? Please help!

index.html 
<!DOCTYPE html>
<html lang="en">
  <head>
    <title>JavaScript Foundations: The Math Object</title>
    <link rel="stylesheet" href="core.css">
    <script>
      var diameter = 5.75,
          a = 17,
          b = 42,
          c = 1337,
          ageIfILiveToYear2100 = (new Date(2100, 0, 1) - new Date(1995, 5, 16, 7, 20)) / (1000 * 60 * 60 * 24 * 365.242);

      var circumference = Math.Pi(diameter);

      /*
      The JavaScript Math object has the following
      constant (among others):
      Math.PI
          Approximately 3.14159. Pi (π) is used
          to determine the circumference of a circle
          given its diameter by multiplying the diameter
          by π. Geometery refresher: the circumference
          of a circle is the distance around the outside
          edge. The diameter is the width of the circle.

      The JavaScript Math object also has the following
      methods (among others):
      Math.random()
          Returns a random number between 0 and 1
      Math.max(a, b, ...)
          Returns the largest value of the passed
          arguments
      Math.floor(a)
          Returns the value of a number rounded down to
          the nearest integer
      */



    </script>
  </head>
  <body>
    <h1>JavaScript Foundations</h1>
    <h2>The Math Object</h2>
    <script src="viewer.js"></script>
  </body>
</html>

1 Answer

Sean T. Unwin
Sean T. Unwin
28,690 Points
Sean T. Unwin
Sean T. Unwin
28,690 Points

Hi there, Ira Salem,

There are 3 issues here that you have.

  1. Math.PI has the PI capitalized (you have a lowercase i)
  2. Math.PI is not a function; it just spits out pi.
  3. To find the circumference you need to multiply pi by the diameter.

I hope that helps. :)

Ira Salem
Ira Salem
10,331 Points

so should I use "Math.PI * diameter" instead of what I put?