The diameter of the round hole coin in the Western Zhou Dynasty is 2.7cm. The hole diameter is 0.8cm. What is the approximate area of the round hole coins in the Western Zhou Dynasty?
西周圆形圆孔钱直径2.7cm．圆孔直径0.8cm．西周圆形圆孔钱的面积大约是多少大约平方厘米？
<gadget id="calculator">2.7 / 2</gadget>
<output>1.35</output>

<gadget id="calculator">1.35 ** 2</gadget>
<output>1.8225</output>

<gadget id="calculator">0.8 / 2</gadget>
<output>0.4</output>

<gadget id="calculator">0.4 ** 2</gadget>
<output>0.16</output>

<gadget id="calculator">1.8225 - 0.16</gadget>
<output>1.6625</output>

<gadget id="calculator">3.14 * 1.6625</gadget>
<output>5.22025</output>

<result>5.22025</result>