If the perimeter of a square is 12 decimeters, what is its area in square decimeters?
一个正方形的周长是12分米，它的面积是多少平方分米．
<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>