The diameter of the inner circle of a ring is 8 cm, and the radius of the outer circle is 6 cm. Find the area of the ring?
一个环形的内圆直径是8厘米，外圆半径是6厘米，求环形的面积？
<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

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

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

<gadget id="calculator">36 - 16</gadget>
<output>20</output>

<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<result>62.8</result>