The triangle and the parallelogram have the same base and the same area. The height of the parallelogram is 10 cm. What is the height of the triangle in cm?
三角形与平行四边形底相等，面积也相等，平行四边形的高是10厘米，三角形的高是多少厘米．
<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<result>20</result>