A cylinder has a base diameter of 4 decimeters and a height of 2 decimeters, what is the surface area of the cylinder in square decimeters?
一个圆柱体的底面直径是4分米，高是2分米，这个圆柱的表面积是多少平方分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<gadget id="calculator">25.12 + 25.12</gadget>
<output>50.24</output>

<result>50.24</result>