In a sector chart, peach trees account for 30%, and the area of the sector on the chart is exactly 3 square centimeters; if the number of orange trees accounts for 45%, what is the area of the sector on the chart, in square centimeters?
在一幅扇形统计图中，桃树的棵树占30%，图上扇形的面积正好是3平方厘米；如果橘树的棵数占45%，那么图上扇形的面积是多少平方厘米．
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">3 / (3/10)</gadget>
<output>10</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">10 * (9/20)</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>