What is the area of a semicircular glass mirror whose circumference is 5.14dm?
一个周长是5.14dm的半圆形玻璃镜，它的面积是多少平方分米？
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

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

<gadget id="calculator">3.14 * (1/2)</gadget>
<output>1.57</output>

<result>1.57</result>