title: Is-A vs Has-A relationship
body: <p>Newbie Question which my course instructor has effectively confused the tar out of me.
  Is-A relationship is when say a Dog is a animal.  Then you'd make Animal be the Base class with Dog as a derivative class.</p>
  
  <p>But for our Class Project I have to make a class based on an interface.  With a separate class which only has one method to give a random number.  Seemingly they aren't really related, but I have to call the randomNumber Method from the main class.</p>
  
  <p>His question during the instructions (which are terrible) say to figure out if this is an IS-A or HAS-A relationship.  Based on the facts I'd say this is a HAS-A relationship, but I have no idea how to reference the class, but to make a variable assigned to the class so I can use it.</p>
  
  <p>Is there another way to Reference the class which I don't know?</p>
  
  <pre><code>Devices randomMeasure = new Devices();  //Random measurement Class
  this.mostRecentMeasure = randomMeasure.GetMeasurement();
  </code></pre>