A cone has a base area of 30 cm2 and a volume of 90 cm3, which is 9 cm3 more than a cylinder of the same height. What is the area of the base of the cylinder in square centimetres.
一个圆锥体的底面积是30平方厘米，体积是90立方厘米，比与它等高的圆柱体体积多9立方厘米．圆柱体的底面积是多少平方厘米．
<gadget id="calculator">90 - 9</gadget>
<output>81</output>

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

<gadget id="calculator">90 * (1/10)</gadget>
<output>9</output>

<gadget id="calculator">81 / 9</gadget>
<output>9</output>

<result>9</result>