The upper base, lower base and height of a right-angled trapezoid are 10dm, 12dm and 8dm respectively, what is its area?
一个直角梯形的上底、下底和高分别是10dm、12dm和8dm，它的面积是多少．
<gadget id="calculator">10 + 12</gadget>
<output>22</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">22 * 4</gadget>
<output>88</output>

<result>88</result>