A circular iron sheet has an outer radius of 8 cm and an inner radius of 6 cm. What is the area of this iron sheet in square centimeters?
一块环形铁皮，外半径是8厘米，内半径是6厘米，这块铁皮的面积是多少平方厘米？
<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

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

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

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

<gadget id="calculator">200.96 - 113.04</gadget>
<output>87.92</output>

<result>87.92</result>