The perimeter of a rectangle is 40 cm. If the length and width are increased by 5 cm at the same time, the area of the rectangle will increase by how many square centimeters.
一个长方形的周长是40厘米，如果把长和宽同时增加5厘米，则长方形的面积就要增加多少平方厘米．
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">5 * 20</gadget>
<output>100</output>

<gadget id="calculator">100 + 25</gadget>
<output>125</output>

<result>125</result>