<?php
    
    /* Note: all angles in degrees */
    
    /* Draw an arc length from $start_a -> $end_a using
       radius $radius (counter-clockwise) */
    pdf_arc($pdf_r, PAGE_WIDTH/2, PAGE_HEIGHT/2, $radius, $start_a, $end_a);
    pdf_stroke($pdf_r);
    
    /* Draw an arc length from $start_a -> $end_a using
       radius $radius (clockwise) */
    pdf_arcn($pdf_r, PAGE_WIDTH/2, PAGE_HEIGHT/2, $radius, $start_a, $end_a);
    pdf_stroke($pdf_r);
    
    /* Draw a circle of radius $radius */
    pdf_circle($pdf_r, PAGE_WIDTH/2, PAGE_HEIGHT/2, $radius);
    pdf_stroke($pdf_r);
?>