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float theta=0;
float radius=240;
void setup(){
size(480,480);
background(0);
stroke(255,100);
noFill();
}
void draw(){
var r=radius;
float x=width/2+r*cos(theta);
float y=height/2+r*sin(theta);
triangle(width/2,height/4,width/2,3*height/4,x,y);
theta+=0.02;
if(theta>=TWO_PI){
background(0);
theta=0;
}
}