The length of the classroom is 7 meters, the width is 5.5 meters, and the height is 3.4 meters. To paint the roof and surrounding walls of this classroom, excluding the doors, windows and blackboards, the area is 25 square meters. How many square meters is the painted area?
教室的长7米，宽5.5米，高3.4米．要粉刷这间教室的屋顶和四周墙壁，除去门窗和黑板面积25平方米，粉刷的面积是多少平方米？
<gadget id="calculator">42.5 - 25</gadget>
<output>17.5</output>

<gadget id="calculator">38.5 + 17.5</gadget>
<output>56</output>

<result>56</result>