On a piece of grass, a lamb is tied to a stake by the owner with a 6-meter-long rope to eat grass. If 0.5 meters of the rope are used to tie the stake and tie a knot, how much grass can the lamb eat? ?
在一片草地上，一只小羊被主人用一根6米长的绳子拴在木桩上吃草，如果拴桩打结用去绳子0.5米，这只小羊能吃到草的面积有多大？
<gadget id="calculator">6 - 0.5</gadget>
<output>5.5</output>

<gadget id="calculator">5.5 ** 2</gadget>
<output>30.25</output>

<gadget id="calculator">3.14 * 30.25</gadget>
<output>94.985</output>

<result>94.985</result>