The perimeter of an isosceles triangle is 20 cm, the waist is 8 cm, and the height of the base is 6 cm. What is its area in square centimeters?
等腰三角形的周长是20厘米，腰是8厘米，底边上的高是6厘米，它的面积是多少平方厘米．
<gadget id="calculator">20 - 8 - 8</gadget>
<output>4</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<result>12</result>