​

// create a variable to hold angle rotation values

​

function setup(){

    createCanvas(400, 400);

}

function draw(){

    background(240);

​

// update rotation values to pass to rotate

​

    // move the origin to the pivot point

    translate(); 

​

    // then rotate the grid around the pivot point

​

    rotate();

​

    // and draw the square at the origin

    fill(0);

    rect(0, 0, 100, 100);

}