Don't understand the parameter of rotate ?

Question

ctx.fillStyle = "#FF0000";
ctx.fillRect(10,10, 100, 100);

ctx.rotate( (Math.PI / 180) * 25); //rotate 25 degrees.

ctx.fillStyle = "#0000FF";
ctx.fillRect(10,10, 100, 100);
what is (Math.PI/180) ? what does this mean?

Answer 1

radians

Answer 2

1=nig
2=nog

Answer 3

radians

Answer 4

radians

Answer 5

radians

Answer 6

radians