A square with a side length of 12 cm, draw the largest circle inside, subtract the inner circle, what are the perimeter and area of the remaining part?
一个边长为12厘米的正方形，往里面画一个最大的圆，减掉里面的圆形，剩下的部分的周长和面积分别是多少？
<gadget id="calculator">12 * 12</gadget>
<output>144</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">3.14 * 36</gadget>
<output>113.04</output>

<gadget id="calculator">144 - 113.04</gadget>
<output>30.96</output>

<result>30.96</result>