A circular iron sheet processed by Uncle Li has an outer radius of 10cm and an inner radius of 6cm. What is its area?
李伯伯加工的一个圆环铁片，它的外圆半径是10cm，内圆半径是6cm．它的面积是多少？
<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

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

<gadget id="calculator">100 - 36</gadget>
<output>64</output>

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

<result>200.96</result>