right triangle, the three side lengths are 0.3 decimeters, 0.4 decimeters, 0.5 decimeters, what is the area of this triangle in square decimeters?
一个直角三角形，三条边长分别是0.3分米、0.4分米、0.5分米，这个三角形的面积是多少平方分米．
<gadget id="calculator">0.4 / 2</gadget>
<output>0.2</output>

<gadget id="calculator">0.3 * 0.2</gadget>
<output>0.06</output>

<result>0.06</result>