The area of the trapezoid is 50 square centimeters, the sum of the upper and lower bases is 20 centimeters, find the height of the trapezoid.
梯形的面积是50平方厘米，上、下底的和是20厘米，求梯形的高．
<gadget id="calculator">2 / 20</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">50 * (1/10)</gadget>
<output>5</output>

<result>5</result>