The area of a trapezoid is 30 square centimeters, the sum of the upper and lower bases is 6 centimeters, what is the height in centimeters?
一个梯形面积是30平方厘米，上底与下底的和是6厘米，高是多少厘米．
<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">30 * (1/3)</gadget>
<output>10</output>

<result>10</result>