Draw the largest semicircle on a rectangular piece of paper with a length of 6 cm and an area of 24 square centimeters. What is the area of this semicircle in square centimeters?
在长为6cm，面积为24平方厘米的长方形纸上画一个最大的半圆，这个半圆的面积是多少平方厘米．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">3.14 * (9/2)</gadget>
<output>14.13</output>

<result>14.13</result>