A square row is reduced by 1:5, the perimeter of the new square is 12cm, what is the original perimeter.
一个正方行按1：5缩小，新的正方形周长12cm，原来周长是多少．
<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">15 * 4</gadget>
<output>60</output>

<result>60</result>