It is known that the upper base of the trapezoid is 3cm, the lower base is 5.2cm, and the height is 4cm. What is the area of the parallelogram formed by two such trapezoids?
已知梯形上底为3cm，下底是5.2cm，高是4cm，两个这样的梯形拼成的平行四边形的面积是多少．
<gadget id="calculator">3 + 5.2</gadget>
<output>8.2</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">8.2 * 2 * 2</gadget>
<output>32.8</output>

<result>32.8</result>