The lateral area of a cylinder is 188.4dm**2, and the radius of the base is 2dm. How tall is it?
一个圆柱的侧面积是188.4dm**2，底面半径是2dm．它的高是多少？
<gadget id="calculator">2 * 3.14 * 2</gadget>
<output>12.56</output>

<gadget id="calculator">188.4 / 12.56</gadget>
<output>15</output>

<result>15</result>