If the longest side of an isosceles right triangle is 4 cm, what is the area of the isosceles right triangle?
一个等腰直角三角形的最长边4厘米，这个等腰直角三角形的面积是多少平方厘米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">4 * 1</gadget>
<output>4</output>

<result>4</result>