A fence can just enclose an equilateral triangle vegetable field with a side length of 20 meters. If it is changed to a square vegetable field, how big is the square vegetable field?
一条篱笆正好可以围成一个边长是20米的正三角形菜地，如果改围成正方形菜地，围成的正方形菜地有多大？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">20 * (3/4)</gadget>
<output>15</output>

<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<result>225</result>