The area of a trapezoid is 30 square centimeters. If its upper and lower bases are reduced to one-fifth of its original size and its height remains the same, what is its area?
一个梯形的面积是30平方厘米，如果它的上底和下底缩小到原来的五分之一，高不变，则它的面积是多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 * (1/5)</gadget>
<output>6</output>

<result>6</result>