If the radius of a circle is increased by 4 times, how many times will its area be increased
一个圆的半径扩大4倍，它的面积扩大多少倍
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<gadget id="calculator">50.24 / 3.14</gadget>
<output>16</output>

<result>16</result>