In math class, Xiaolan cut a circular piece of paper with a radius of 3 cm. Can you guess how many square centimeters of square paper she needs to prepare at least.
数学课上，小兰剪了一个半径为3厘米的圆形纸片，你能猜出她至少要准备多少平方厘米的正方形纸片．
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<result>36</result>