<?xml version="1.0" encoding='utf-8'?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">
<wml>
<card id="card1" title="Opaque set - Page 3 - Wikipedia">
<p>
<a accesskey="1" href="page.php?w=Opaque_set&amp;p=2">1.Previous</a><br />
<a accesskey="3" href="page.php?w=Opaque_set&amp;p=4">3.Next</a>
</p>
<p>possible opaque set for the square, and for most other shapes this problem similarly remains unsolved. The shortest opaque set for any bounded <a href="page.php?w=convex_set">convex set</a> in the plane has length at most the <a href="page.php?w=perimeter">perimeter</a> of the set, and at least half the perimeter. For the square, a slightly stronger lower bound than half the perimeter is known. Another convex set whose opaque sets are commonly studied is the <a href="page.php?w=unit_circle">unit circle</a>, for which the shortest <a href="page.php?w=connected_set">connected</a></p><p>
<a accesskey="1" href="page.php?w=Opaque_set&amp;p=2">1.Previous</a><br />
<a accesskey="3" href="page.php?w=Opaque_set&amp;p=4">3.Next</a>
</p>

<do type="prev" label="Search">
        <go href="search.wml"/>
</do>

</card>
</wml>
