The perimeter of a rectangular piece of paper is 64 cm, and the ratio of length to width is 5:3. If it is cut into the largest semicircle, what is the area of the semicircle?
一个长方形纸片的周长是64厘米，长与宽的比是5：3，如果用它剪成一个最大的半圆形，那么这个半圆形纸片的面积是多少？
<gadget id="calculator">64 / 2</gadget>
<output>32</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">32 * (5/8)</gadget>
<output>20</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

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

<gadget id="calculator">3.14 * 100 * (1/2)</gadget>
<output>157</output>

<result>157</result>