The height of a cylinder is 15 cm and the radius of the base is 5 cm. What is its surface area?
一个圆柱的高是15厘米，底面半径是5厘米，它的表面积是多少？
<gadget id="calculator">2 * 3.14 * 5 * 15</gadget>
<output>471</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

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

<gadget id="calculator">471 + 157</gadget>
<output>628</output>

<result>628</result>