If a sheep is tied to the center of a rectangular grass field with a length of 40 meters and a width of 30 meters, and the rope for tying the sheep is 8 meters long, how much grass can the sheep eat?
把一只羊拴在一块长40米，宽30米的长方形草地的中央，拴羊的绳子长8米，这只羊可能吃到多大面积的草？
<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

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

<result>200.96</result>