Divide a circle with a radius of 5 centimeters into several equal parts of small sectors and assemble them into an approximate rectangle. What is the length of this rectangle in centimeters?
把一个半径为5厘米的圆平均分成若干等份的小扇形，再拼成一个近似的长方形，这个长方形的长是多少厘米．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">2 * 3.14 * (5/2)</gadget>
<output>15.7</output>

<result>15.7</result>