rst argument</p></dd></dl><dl><dt class="spec value" id="val-perimeter"><a href="#val-perimeter" class="anchor"></a><code><span class="keyword">val</span> perimeter : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> float</code></dt><dt class="spec value" id="val-area"><a href="#val-area" class="anchor"></a><code><span class="keyword">val</span> area : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> float</code></dt><dt class="spec value" id="val-proj_x"><a href="#val-proj_x" class="anchor"