What is the area of a triangle whose base is 18 cm and height is 9 cm?
一个三角形底是18厘米，高是9厘米，它的面积是多少平方厘米．
<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">18 * (9/2)</gadget>
<output>81</output>

<result>81</result>