Draw the largest semicircle in a rectangle whose length is 8 cm and width is 6 cm. What is the area of this semicircle in square centimeters?
在一个长是8厘米，宽是6厘米的长方形中画一个最大的半圆，这个半圆的面积是多少平方厘米．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

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

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">3.14 * 8</gadget>
<output>25.12</output>

<result>25.12</result>