int n = 5;
float[] xArray = new float[n]; //allocate memory for 5 points
float[] yArray = new float[n];
void setup(){
  float angle = 2 * PI / n; //divide the circle in n sections
  for(int i =0; i< n; i++){ //create points along a circle
    xArray[i] = 50. + 30. * sin(angle*i);
    yArray[i] = 50. + 30. * cos(angle*i);
  }
}
void draw (){
  beginShape(POLYGON);
  for(int i = 0; i < n; i++)
    vertex(xArray[i],yArray[i]);
  endShape(CLOSE);
}