A triangle has two sides with a right angle of 2.5 centimeters long, what is the area of the triangle in square centimetres?
一个三角形，夹直角的两条边都长2.5厘米，这个三角形的面积是多少平方厘米．
<gadget id="calculator">2.5 / 2</gadget>
<output>1.25</output>

<gadget id="calculator">2.5 * 1.25</gadget>
<output>3.125</output>

<result>3.125</result>