The perimeter of the base of a cube is 28dm, what is its surface area in cm**2.
一个正方体的底面周长是28dm，它的表面积是多少cm**2．
<gadget id="calculator">28 / 4</gadget>
<output>7</output>

<gadget id="calculator">7 * 7 * 6 * 1 * 100</gadget>
<output>29_400</output>

<result>29_400</result>