If the base of a triangle is 9 decimeters and the height is 2 decimeters, what is its area?
一个三角形的底是9分米，高是2分米，它的面积是多少平方分米．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">9 * 1</gadget>
<output>9</output>

<result>9</result>