Xiaogang drew a circle with a radius of 3 cm, and painted the circle into two parts, red and yellow. Among them, the red part occupies (2/3) the area of the circle, so how many square centimeters is the area of the yellow part?
小刚画了一个半径是3厘米的圆，把圆面涂成红色和黄色两部分．其中红色部分占圆面积的(2/3)，则黄色部分面积是多少平方厘米？
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3.14 * 9 * (1/3)</gadget>
<output>9.42</output>

<result>9.42</result>