The width of a rectangle is 7 meters and its length is 3 meters shorter than its length. What is its area in square meters?
长方形的宽是7米，比长短3米，它的面积是多少平方米
<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<gadget id="calculator">10 * 7</gadget>
<output>70</output>

<result>70</result>