Mom made a fabric cover for Xiaoming's kettle. It is known that the kettle is cylindrical, the bottom diameter is 10cm, and the height is 20cm. How much fabric should be used to make this cover?
妈妈给小明的水壶做了一个布套，已知水壶是圆柱形的，底面直径是10cm，高是20cm，做这个布套至少布料？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

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

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">3.14 * 10 * 20</gadget>
<output>628</output>

<gadget id="calculator">78.5 + 628</gadget>
<output>706.5</output>

<result>706.5</result>