In a rectangle with a length of 5 cm and a width of 3 cm, draw the largest semicircle with a circumference of cm. How many
在长5厘米，宽3厘米的长方形中，画一个最大的半圆，这个半圆的周长是厘米．多少
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">3.14 * (5/2)</gadget>
<output>7.85</output>

<gadget id="calculator">7.85 + 5</gadget>
<output>12.85</output>

<result>12.85</result>