A glass aquarium without a cover has the shape of a cube with sides 3dm long. At least how many square decimeters of glass is needed to make this fish tank.
一个没有盖的玻璃鱼缸的形状是正方体，棱长3dm．制作这个鱼缸时至少需要玻璃多少平方分米．
<gadget id="calculator">3 * 3 * 5</gadget>
<output>45</output>

<result>45</result>