If a parallelogram with a base of 10 cm and a height of 6 cm is stretched into a rectangle, the area will increase by 20 square centimeters compared to the original one. How many centimeters is the width of the rectangle?
把一个底10厘米，高6厘米的平行四边形，拉成长方形后，面积比原来增加了20平方厘米，长方形的宽是几厘米？
<gadget id="calculator">10 * 6</gadget>
<output>60</output>

<gadget id="calculator">60 + 20</gadget>
<output>80</output>

<gadget id="calculator">80 / 10</gadget>
<output>8</output>

<result>8</result>