Use a 90-meter-long fence to form a rectangular vegetable field. The ratio of the length to width of this vegetable field is 8:7. How many square meters is the area of this vegetable field?
用90米长的篱笆围成一个长方形菜地，这块菜地长与宽的比是8：7，这块菜地的面积是多少平方米？
<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<gadget id="calculator">8 + 7</gadget>
<output>15</output>

<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">45 * (8/15)</gadget>
<output>24</output>

<gadget id="calculator">45 - 24</gadget>
<output>21</output>

<gadget id="calculator">24 * 21</gadget>
<output>504</output>

<result>504</result>