A square of grass with a side length of 4 meters has a tree at each opposite corner, and a sheep is tied to each tree. The rope is 3 meters long. What is the area of the grass that two sheep can eat?
一块边长是4米的正方形草地，两对角各有一棵树，树上各拴着一只羊，绳子长3米，问两只羊能吃到草地的面积是多少？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">(1/4) * 3.14 * 16</gadget>
<output>12.56</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 4 * 4</gadget>
<output>8</output>

<gadget id="calculator">12.56 - 8</gadget>
<output>4.56</output>

<gadget id="calculator">4.56 * 2</gadget>
<output>9.12</output>

<result>9.12</result>