The height of a cuboid is reduced by 6 cm to form a cube, and its surface area is reduced by 72 cm2. What is the volume of this cuboid?
一长方体的高减少6厘米就成一个正方体，其表面积减少72平方厘米，这个长方体的体积是多少．
<gadget id="calculator">72 / 6 / 4</gadget>
<output>3</output>

<gadget id="calculator">3 + 6</gadget>
<output>9</output>

<gadget id="calculator">3 * 3 * 9</gadget>
<output>81</output>

<result>81</result>