The width of the textbook is X cm, and the length is 2 cm more than the width. What is the area of the textbook in square centimeters?
课本的宽为X厘米，长比宽多2厘米，课本的面积是多少平方厘米．
<gadget id="calculator">2 + 2</gadget>
<output>4</output>

<result>4</result>