If the width of a rectangle is 8 decimeters and the length is twice the width, what is the area in square decimeters?
一个长方形的宽是8分米，长是宽的2倍，面积是多少平方分米．
<gadget id="calculator">8 * 2 * 8</gadget>
<output>128</output>

<result>128</result>