A cylinder has a surface area of 345.4 square centimeters and a base radius of 5 centimeters. Find its height.
一个圆柱，表面积是345.4平方厘米，底半径是5厘米，求它的高．
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25 * 2</gadget>
<output>157</output>

<gadget id="calculator">345.4 - 157</gadget>
<output>188.4</output>

<gadget id="calculator">3.14 * 5 * 2</gadget>
<output>31.4</output>

<gadget id="calculator">188.4 / 31.4</gadget>
<output>6</output>

<result>6</result>