A square with a side length of 6 decimeters is composed of two identical right triangles. What is the area of one of the right triangles?
一个边长是6分米的正方形是由两个完成相同的直角三角形拼成的，其中一个直角三角形的面积是多少平方分米．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>