A cylinder has a base diameter of 4 meters and a height of 6 meters. Cutting the cylinder in half along the diameter of the base increases the surface area by how many square meters.
一个圆柱体的底面直径是4米，高是6米．沿着底面直径把圆柱体切成两半，表面积增加了多少平方米．
<gadget id="calculator">4 * 6 * 2</gadget>
<output>48</output>

<result>48</result>