How many centimeters of rope is needed to bind together three cylindrical plastics with a base diameter of 10 centimeters.
要将底面直径是10厘米的3个圆柱形塑料捆在一起，至少需要多少厘米的绳子．
<gadget id="calculator">3.14 * 10</gadget>
<output>31.4</output>

<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">31.4 + 30</gadget>
<output>61.4</output>

<result>61.4</result>