There is a cuboid with a square base and a height of 18 cm, and its side is just a square. Find the volume of this cuboid.
有一个长方体，底面是正方形，高18厘米，侧面展开正好是一个正方形，求这个长方体的体积．
<gadget id="calculator">18 / 4</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">(9/2) * (9/2) * 18</gadget>
<output>729/2 = around 364.5</output>

<result>729/2 = around 364.5</result>