A rectangular frame with a length of 80 cm and a width of 50 cm is drawn into a parallelogram, and the area is reduced by 80 cm2. Find the height of the parallelogram.
把一个长为80厘米，宽为50厘米的长方形框拉成一个平行四边形，这时面积减少了80平方厘米．求平行四边形的高．
<gadget id="calculator">80 * 50</gadget>
<output>4_000</output>

<gadget id="calculator">4_000 - 80</gadget>
<output>3_920</output>

<gadget id="calculator">3_920 / 80</gadget>
<output>49</output>

<result>49</result>