How do I draw an half Circle in opengl

I use this method which works perfectly to draw a full circle(might be typos in code text I wrote from memory): ``` drawCircle(GLAutodrawble drawble){ GL gl = drawble.getGL(); gl.glTranslatef(0.0f,0.0f,-7.0f); gl.glBeginf(GL_LINE_LOOP); gl.glColorf(0.0f,0.0f,0.0); final dobule PI = 3.141592654; double angle = 0.0; int points = 100; for(int i =0; i < points;i++){ angle = 2 * PI * i / points; gl.glVertexf((float)Math.cos(angle),(float)Math.sin(angle)); } gl.glScalef(1.0f,1.0f,0.0f); gl.glEnd(); } ``` I want to use the same priciples to make method to make a half circle, I don't get my head around what I should do with the cos sin stuff. Can anyone take a look and help me. Thanks goes to all that thakes a look at the problem!