Two cylinders of equal height, the radius of the larger cylinder is twice the radius of the smaller cylinder, the volume of the smaller cylinder is 20 cubic centimeters, what is the volume of the larger cylinder in cubic centimeters?
高相等的两个圆柱，大圆柱的半径是小圆柱半径的2倍，小圆柱的体积是20立方厘米，大圆柱的体积是多少立方厘米．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>