The perimeter of an equilateral triangle is 18cm and the height is 36cm. What is its area in square centimetres?
一个等边三角形的周长是18cm，高是36cm，它的面积是多少平方厘米．
<gadget id="calculator">18 / 3</gadget>
<output>6</output>

<gadget id="calculator">36 / 2</gadget>
<output>18</output>

<gadget id="calculator">6 * 18</gadget>
<output>108</output>

<result>108</result>