The diagonal of a square is 12cm long, what is the area of the square in cm**2.
正方形的对角线长12cm，这个正方形的面积为多少cm**2．
<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">12 * 6</gadget>
<output>72</output>

<result>72</result>