The base of a triangle is 15 cm. If the base is reduced by 3 cm, the area is reduced by 18 cm2. What is the area of the original triangle?
一个三角形的底是15厘米，如果底缩小3厘米，面积就缩小18平方厘米，原来三角形的面积是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">18 * (2/3)</gadget>
<output>12</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">15 * 6</gadget>
<output>90</output>

<result>90</result>