The perimeter of a rectangle is 300 cm, and the length is twice the width. What is the area of the rectangle?
一个长方形的周长是300厘米，长是宽的2倍，这个长方形的面积是多少平方厘米？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">300 / 2 / 3</gadget>
<output>50</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">50 * 100</gadget>
<output>5_000</output>

<result>5_000</result>