How many square centimeters of glass is needed to make a cup with a radius of 8 centimeters and a height of 9 centimeters without a lid?
做一个半径是8厘米，高是9厘米的无盖水杯，至少需要多少平方厘米的玻璃？
<gadget id="calculator">8 ** 2</gadget>
<output>64</output>

<gadget id="calculator">3.14 * 64</gadget>
<output>200.96</output>

<gadget id="calculator">3.14 * 2 * 8 * 9</gadget>
<output>452.16</output>

<gadget id="calculator">200.96 + 452.16</gadget>
<output>653.12</output>

<result>653.12</result>