The sum of the upper and lower bases of a trapezoid is 20 cm, the height is 15 cm, and the base of a triangle with the same area is 12 cm, so what is the height of this triangle?
一个梯形的上下底的和是20厘米，高是15厘米，和它面积相等的三角形底是12厘米，那么这个三角形的高是多少？
<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">20 * (15/2)</gadget>
<output>150</output>

<gadget id="calculator">2 / 12</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">150 * (1/6)</gadget>
<output>25</output>

<result>25</result>