The base of a triangle is 5cm, the height is 4cm, what is its area in cm**2.
一个三角形的底是5cm，高是4cm，它的面积是多少cm**2．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<result>10</result>