title: Core Graphics - drawing a line at an angle
body: <p>I've been searching struggling with this for a while now and need some help. I just want to draw 25 lines from the centre of my display (160,200) at 14.4 degrees separation. I have been using this line of code in a for loop where x is the 14.4 degree multiplier -</p>
  
  <pre><code>    UIImage*backgroundImage = [UIImage imageNamed:@"Primate Background Only.png"];
  [backgroundImage drawInRect:CGRectMake(0, 0, 320, 480)];
  </code></pre>
  
  <p>//  Draw Outer Circle </p>
  
  <pre><code>rect = CGRectMake(0.0, 35.0, 320.0, 320.0);     
  CGContextRef contextRef = UIGraphicsGetCurrentContext();                // Get the contextRef
  CGContextSetLineWidth       (contextRef, 0.5);                  // Set the border width
  CGContextSetRGBFillColor    (contextRef, (219.0f/255.0f), (219.0f/255.0f), (219.0f/255.0f), 0.05f);             // Set the circle fill color to GREEN
  CGContextSetRGBStrokeColor  (contextRef, 0.0, 0.0, 0.0, 0.2);           // Set the circle border color to BLACK     
  CGContextFillEllipseInRect      (contextRef, rect);                 // Fill the circle with the fill color
  CGContextStrokeEllipseInRect    (contextRef, rect);                 // Draw the circle border
  </code></pre>
  
  <p>//  Draw Inner Circle</p>
  
  <pre><code>rect = CGRectMake(25.0, 60.0, 270.0, 270.0);                        // Get the contextRef
  CGContextSetLineWidth       (contextRef, 0.5);                  // Set the border width
  CGContextSetRGBFillColor    (contextRef, (219.0f/255.0f), (219.0f/255.0f), (219.0f/255.0f), 0.25f);
  CGContextSetRGBStrokeColor  (contextRef, 0.0, 0.0, 0.0, 0.2);           // Set the circle border color to BLACK     
  CGContextFillEllipseInRect      (contextRef, rect);                 // Fill the circle with the fill color
  CGContextStrokeEllipseInRect    (contextRef, rect);     
  </code></pre>
  
  <p>//  Draw Segments   </p>
  
  <pre><code>CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextTranslateCTM(context, 0.0, 0.0);           
      for (x=1; x&lt;26; x++) {  
  
          CGContextSetLineWidth       (context, 0.5);
          CGContextSetRGBStrokeColor  (context, 0.0, 0.0, 0.0, 0.25);
          CGContextMoveToPoint        (context, 160, 200);                
          CGContextAddLineToPoint     (context, (160.0 * (cos((x*14.4)*(M_PI/180)))), (160.0 * (sin((x*14.4)*(M_PI/180)))));                      //  The angle is in degrees
          CGContextAddLineToPoint     (context, 200, 65);
          CGContextAddLineToPoint     (context, 160, 200);            
          CGContextStrokePath(context);                           // Why is this not showing both line color and infill?
          CGContextSetFillColorWithColor   (context, [UIColor whiteColor].CGColor);       
          CGContextFillPath           (context);
          CGContextRef context = UIGraphicsGetCurrentContext();
      }           
  </code></pre>
  
  <p>(I intended to post an image here but it won't permit me!)</p>
  
  <p>Can someone please correct my trig functions. This is meant to draw 25 lines clockwise from 12:00 o'clock to 24:00. Instead it draws backwards only 90 degrees then returns, all lines are way out in length also.</p>
  
  <p>Very grateful</p>
  
  <p>Above is a bigger sample of the code used to draw tow outer circles and the interior segments as requested. I'll try and upload the image next.</p>
  
  <p><img src="https://i.stack.imgur.com/udFT3.png" alt="enter image description here"></p>