The base of the triangle is 2.5 cm, the height is 4 cm, what is the area in square centimeters?
三角形的底是2.5厘米，高是4厘米，面积是多少平方厘米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2.5 * 2</gadget>
<output>5</output>

<result>5</result>