int x = 250;
int y = 250;

int r = 200;
void setup() {
  size(700, 700);

}

void draw() {
background(100);
for (int a= 0; a < 360;a++) {
float x1 = x + r * cos(a);
float y1 = y + r * sin(a);
line(int(x1),int(y1),int(x1)+100,int(x1)+100);
}
}