The base of a triangle is 15 cm, the height is 9 cm, what is the area?
一个三角形底是15厘米，高是9厘米，求面积？
<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">15 * (9/2)</gadget>
<output>135/2 = around 67.5</output>

<result>135/2 = around 67.5</result>