The upper base of a trapezoidal board is 10 cm long, the lower base is 7 cm longer than the upper base, and the height is 6 cm. What is the area of this board?
一块梯形木板的上底长10厘米，下底比上底长7厘米，高是6厘米，这块木板的面积是多少？
<gadget id="calculator">10 + 7</gadget>
<output>17</output>

<gadget id="calculator">10 + 17</gadget>
<output>27</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">27 * 3</gadget>
<output>81</output>

<result>81</result>