right triangle whose hypotenuse is 20 cm, and the difference between the two sides is 4 cm, what is the area of this right triangle?
一个斜边是20厘米的直角三角形，两条直角边之差是4厘米，这个直角三角形面积是多少平方厘米？
<gadget id="calculator">12 + 4</gadget>
<output>16</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">12 * 8</gadget>
<output>96</output>

<result>96</result>