The length of an arc is 18.84 cm, and the central angle is 270°. What is the radius of this arc in cm?
一弧长为18.84厘米，圆心角270°，这弧的半径为多少厘米．
<gadget id="calculator">180 / 3.14 / 270</gadget>
<output>0.212314</output>

<gadget id="calculator">18.84 * 0.212314</gadget>
<output>3.999996</output>

<result>3.999996</result>