Two Pi radians.

The Java trigonometric functions
are static methods of the `Math`

.
They
take radians for their arguments
(as do such functions in most programming languages).
Here is the complete method:

private void drawStar( int x, int y, int size ) { int endX, endY ; // Six lines radiating from (x,y) for ( int i = 0; i<6; i++ ) { endX = x + (int)(size*Math.cos( (2*Math.PI/6)*i )); endY = y - (int)(size*Math.sin( (2*Math.PI/6)*i )); // Note "-" graph.drawLine( x, y, endX, endY ); } }

The circle is divided into six pieces.
The constant pi is available in Java as `Math.PI`

`(2*Math.PI/6)`

You could do the division and write this as `(Math.PI/3)`

The "-" sign is used for `endY`

because
`y`

increases in value going down.
Using a "+" would also work because of symmetry.