title: Assistance needed writing simple Objective-C program
body: <p>I have been struggling along with an online objective-c class for a few weeks now. I'm feeling very stupid..
  My latest assignment is to write a program that demonstrates a class named Circle by asking the user for the circle's radius, creating a Circle object, and then reporting the circle's area, diameter, and circumference. 
  We should have the following member variables:</p>
  
  <pre><code>radius:  a double
  pi: a double initialized to 3.14159
  </code></pre>
  
  <p>and the following member functions:</p>
  
  <pre><code>setRadius - a mutator function for the radius variable
  getRadius - an accessor function for the radius variable
  getArea - returns the area of the circle, which is calculated as:    area = pi * radius * radius
  getDiameter - returns the diameter of the circle, which is calculated as:   diameter = radius * 2
  getCircumference - returns the circumference of the circle, which is calculated as:   circumference = 2 * pi * radius
  </code></pre>
  
  <p>The member variables of the class should be set as private.</p>
  
  <p>Here is my program so far:</p>
  
  <p>Main:</p>
  
  <pre><code>int main(int argc, const char * argv[])
  {
  
      @autoreleasepool {
  
          int radius;
  
          NSLog(@"Enter the circles radius:");
          scanf ("%d", &amp;radius);
  
  
  
  
  
      }
      return 0;
  }
  </code></pre>
  
  <hr>
  
  <p>Interface:</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  
  //circle class
  
  @interface circle : NSObject
  
  { @private
  
  -(double)      radius;
  -(double)      pi;
  
  }
  
  @property int setRadius, getRadius;
  
  -(double)      getArea;
  -(double)      getDiameter;
  -(double)      getCircumcerence;
  
  
  @end
  </code></pre>
  
  <hr>
  
  <p>Implementation: </p>
  
  <pre><code>#import "circle.h"
  
  @implementation circle
  
  @synthesize setRadius, getRadius;
  
  
  -(double) pi
  {
      pi = 3.14159;
  }
  
  -(double) getArea
  {
      pi * radius * radius;
  }
  
  -(double) getDiameter
  {
      radius * 2;
  }
  
  -(double) getCircumcerence
  {
      2 * pi * radius;
  }
  @end
  </code></pre>
  
  <p>As you can see, I haven't gotten very far. I am confused as how to simply utilize my methods in my main, and am sure I have already made mistakes. </p>
  
  <p>Any advice is appreciated! I really need help, and am short on time.
  Also, this may be far-fetched but if anyone could maybe skype with me and help me through it?
  Thanks!</p>