Cut out the largest square from the circle, the diagonal length of the square is 16 decimeters, what is the remaining area in square decimeters?
从圆里剪下一个最大的正方形，正方形对角线长为16分米，剩下的面积为多少平方分米．
<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

<gadget id="calculator">3.14 * 64</gadget>
<output>200.96</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">16 * 4 * 2</gadget>
<output>128</output>

<gadget id="calculator">200.96 - 128</gadget>
<output>72.96</output>

<result>72.96</result>