Xiaoming's family has a rectangular vegetable field with a perimeter of 120 meters. The ratio of length to width is 7:5. What is the area of this vegetable field in square meters?
小明家有一块周长为120米的长方形菜地，长和宽的比是7：5，这块菜地的面积是多少平方米？
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">120 / 2 / 12</gadget>
<output>5</output>

<gadget id="calculator">5 * 7 * 5 * 5</gadget>
<output>875</output>

<result>875</result>