There is a right triangle, the lengths of the three sides are 3 decimeters, 5 decimeters and 4 decimeters respectively, what is the area of this triangle in square decimeters?
有一个直角三角形，三条边的长度分别为3分米、5分米、4分米，这个三角形的面积是多少平方分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<result>6</result>