The silver part of the disc is a ring, the radius of the inner circle is 2 cm, and the radius of the outer circle is 6 cm. What is the area of the disc in square centimeters?
光盘的银色部分是一个圆环，内圆半径是2厘米，外圆半径是6厘米，光盘的面积是多少平方厘米．
<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

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

<gadget id="calculator">36 - 4</gadget>
<output>32</output>

<gadget id="calculator">3.14 * 32</gadget>
<output>100.48</output>

<result>100.48</result>