There is a circular flower bed with a diameter of 30 meters. A one-meter cobblestone path is to be paved around it. How many square meters is the area of this path?
有一个圆形花坛，直径是30米，要在它的周围铺一条一米的鹅卵石小路，这条小路的面积有多少平方米？
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<gadget id="calculator">16 ** 2</gadget>
<output>256</output>

<gadget id="calculator">15 ** 2</gadget>
<output>225</output>

<gadget id="calculator">256 - 225</gadget>
<output>31</output>

<gadget id="calculator">3.14 * 31</gadget>
<output>97.34</output>

<result>97.34</result>