If the radius of a circle is 3 cm and the central angle is 60 degrees, what is the area of the sector in square centimeters?
一个扇形所在圆的半径为3厘米，圆心角为60度，那么这个扇形的面积为多少平方厘米．
<gadget id="calculator">60 / 360</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">(1/6) * 3.14 * 9</gadget>
<output>4.71</output>

<result>4.71</result>