The diagonal length of a square is 6cm, what is its area in cm**2.
一个正方形的对角线长为6cm，它的面积是多少cm**2．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">6 * 6 * (1/2)</gadget>
<output>18</output>

<result>18</result>