A square tablecloth has a side length of 9 decimeters. If there is a lace around the tablecloth, how many decimeters is the lace length?
一块正方形桌布，边长9分米，如果在桌布的四周围一圈花边，花边长多少分米？
<gadget id="calculator">9 * 4</gadget>
<output>36</output>

<result>36</result>