Put 4 squares with side lengths of 1 cm in a row to form a rectangle. What is the area of the rectangle?
将4个边长都是1厘米的正方形摆成一排拼成一个长方形，这个长方形的面积是多少．
<gadget id="calculator">1 * 1 * 4</gadget>
<output>4</output>

<result>4</result>