The base is a square cuboid, the sum of the lengths of all sides is 80cm, and the known height is 10cm, what is the volume of this cuboid?
底面是正方形的长方体，所有棱长之和是80cm，已知高为10cm，求这个长方体的体积？
<gadget id="calculator">4 * 10</gadget>
<output>40</output>

<gadget id="calculator">80 - 40</gadget>
<output>40</output>

<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<gadget id="calculator">40 / 8</gadget>
<output>5</output>

<gadget id="calculator">5 * 5 * 10</gadget>
<output>250</output>

<result>250</result>