The height of the cylinder remains the same, the radius of the bottom surface is doubled, and the volume is enlarged by how many times
圆柱的高不变，底面半径扩大2倍，体积扩大多少倍
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">4 * 1</gadget>
<output>4</output>

<result>4</result>