Xiaohong measured that the perimeter of a big red cylinder in an ancient building is 18.84 meters. What is the radius of this cylinder in meters?
小红量得一个古代建筑中的大红圆柱的周长是18.84米，这个圆柱的半径是多少米？
<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

<result>3</result>