There is a cuboid whose base is a square, and its sides are exactly a square with a side length of 20 cm. What is the volume of this cuboid in cm**3?
有一个长方体底面是正方形，侧面展开正好是一个边长为20cm的正方形，这个长方体的体积是多少cm**3？
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 5 * 20</gadget>
<output>500</output>

<result>500</result>