Every 5 square pieces of paper with an area of 1 square centimeter are arranged in a row, and 4 rows are arranged to form a rectangle. What is the area of this rectangle in square centimeters?
每5个面积是1平方厘米的正方形纸片摆成一排，摆4排拼成一个长方形．这个长方形的面积是多少平方厘米？
<gadget id="calculator">5 * 4 * 1</gadget>
<output>20</output>

<result>20</result>