There is an old tree in the botanical garden. The rope around it can just form a rectangle with a length of 4 meters and a width of 3 meters. How thick is the old tree?
植物园里有一棵古树，绕它一周的绳子刚好可以围成一个长4米、宽3米的长方形，古树有多粗？
<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<result>14</result>