If a cylinder with a base area of 60cm**2 and a height of 30cm is used to make a cone with the same height as the original cylinder, what is the area of its base?
一个底面积为60cm**2，高为30cm的圆柱，将它的一半用来做一个和原来圆柱一样高的圆锥，则它的底面积是多少？
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">3 / 30</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">60 * 15 * (1/10)</gadget>
<output>90</output>

<result>90</result>