The diameter of a circular field is 10 meters. If the turf is 12 yuan per square meter, how much will it cost to cover the field with turf?
一个圆形场地的直径是10米，若每平方米草皮12元，那么用草皮铺满场地需要多少钱？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">25 * 3.14 * 12</gadget>
<output>942</output>

<result>942</result>