A trapezoid with an upper base of 4 cm can be turned into a square if the upper base is extended by 2 cm. What are the base and height of this trapezoid?
一个梯形，上底是4厘米，如果将上底延长2厘米，则该梯形可以变成一个正方形．这个梯形的下底和高各是多少厘米？
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<result>6</result>