On the grassland, a herdsman uses a 4-meter-long rope to dry a sheep on a wooden stake to graze. How many square meters of grass can this sheep eat at most?
草原上，一位牧民用一根长4米的绳子把一只羊晒在一根木桩上吃草，那这只羊最多能吃到多少平方米的草？
<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<result>50.24</result>