A triangular board, the base is 26 decimeters, 14 decimeters less than the height. What is the area of this triangular board in square decimeters?
一块三角形木板，底是26分米，比高少14分米．这块三角形木板的面积是多少平方分米？
<gadget id="calculator">26 + 14</gadget>
<output>40</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">26 * 20</gadget>
<output>520</output>

<result>520</result>