The perimeter of a rectangular playground is 420 meters, and the ratio of length to width is 4:3. What is the area of the playground in square meters?
一个长方形操场的周长是420米，长与宽的比是4：3．这个操场的面积是多少平方米？
<gadget id="calculator">420 / 2</gadget>
<output>210</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">210 * (4/7)</gadget>
<output>120</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">210 * (3/7)</gadget>
<output>90</output>

<gadget id="calculator">120 * 90</gadget>
<output>10_800</output>

<result>10_800</result>