The length of the hypotenuse of an isosceles right triangle is 18 cm. What is the area of this isosceles right triangle?
一个等腰直角三角形的斜边的长是18厘米，这个等腰直角三角形的面积是多少平方厘米？
<gadget id="calculator">18 / 2 / 2</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">18 * (9/2)</gadget>
<output>81</output>

<result>81</result>