The lengths of the three sides of a right triangle are 15 cm, 12 cm and 9 cm respectively. What is the area of the triangle in square centimeters?
一个直角三角形三条边的长度分别是15厘米、12厘米和9厘米、这个三角形面积是多少平方厘米．
<gadget id="calculator">9 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">12 * (9/2)</gadget>
<output>54</output>

<result>54</result>