size(500,300);
background(255);
strokeWeight(5);
smooth();

float radius = 100;
int centX = 250;
int centY = 150;

stroke(0, 30);
noFill();
ellipse(centX,centY,radius*2,radius*2);

stroke(20, 50, 70);
radius = 10;    
float x, y;
float lastx = -999;
float lasty = -999;
for (float ang = 0; ang  -999) {
    line(x,y,lastx,lasty);
  }
  lastx = x;
  lasty = y;  
}