There is a rectangular meadow 50 meters long and 20 meters wide. A sheep is tied to each of the four corners of the meadow. The length of the rope for each sheep is 5 meters. The area that 4 sheep can eat grass is at most what percentage of the entire grassland area?
有一块长50米，宽20米的长方形草地，在草地四个角各拴一头羊，每头羊的绳长都是5米．4头羊能吃到草的面积，最多占整个草地面积的百分之几？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">50 * 20</gadget>
<output>1_000</output>

<gadget id="calculator">78.5 / 1_000</gadget>
<output>0.0785</output>

<result>0.0785</result>