If a rectangle with a perimeter of 30 cm is cut into two squares, what is the fifth of the area of the square?
周长是30厘米的长方形正好切成两个正方形，这个正方形的面积的五分之一是多少．
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">30 / 6</gadget>
<output>5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 * 5 * (1/5)</gadget>
<output>5</output>

<result>5</result>