If the perimeter of a square is 8 centimeters, what is the area of the square in square centimetres?
一个正方形的周长是8厘米，正方形的面积是多少平方厘米．
<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>