If the perimeter of a square is 10 decimeters, what is its area in square decimeters?
一个正方形的周长是10分米，它的面积是多少平方分米．
<gadget id="calculator">10 / 4</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) * (5/2)</gadget>
<output>25/4 = around 6.25</output>

<result>25/4 = around 6.25</result>