Answer:
Two Pi radians.
So the six lines will be at angles 0, 1*(2pi)/6, 2*(2pi)/6, 3*(2pi)/6, ...
Two Pi radians.
So the six lines will be at angles 0, 1*(2pi)/6, 2*(2pi)/6, 3*(2pi)/6, ...
private void drawStar( Graphics gr, 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 "-"
gr.drawLine( x, y, endX, endY );
}
}
The complete method is shown, above.
The Java trigonometric functions
are static methods of the Math.
They use radians for their arguments.
The circle is divided into six pieces.
The constant pi is available in Java as Math.PI.
There are two pi radians per circle.
One sixth of a circle is (2*Math.PI/6).
The minus sign is used in the calculation of endY because
y increases in value going down.
Using a "+" would also work because of symmetry.
What does (int) do in the statement
endY = y - (int)(size*Math.sin( (2*Math.PI/6)*i ));