The upper base of a right-angled trapezoid is 25 cm. If the lower base is reduced by 15 cm, it becomes a square. What is the area of the original trapezoid in square centimeters?
一个直角梯形的上底是25厘米，如果下底减少15厘米就成了正方形，原来梯形的面积是多少平方厘米．
<gadget id="calculator">25 - 15</gadget>
<output>10</output>

<gadget id="calculator">25 + 10</gadget>
<output>35</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">35 * 5</gadget>
<output>175</output>

<result>175</result>