Make a trapezoidal wrapping paper, the upper base is 14 cm, the lower base is 16 cm, and the height is 10 cm. If you are going to make 300 such wrapping papers, how much paper do you need at least?
做一种梯形的包装纸，上底是14厘米，下底是16厘米，高是10厘米．准备做300个这样的包装纸，至少需要多少纸？
<gadget id="calculator">14 + 16</gadget>
<output>30</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">30 * 5 * 300</gadget>
<output>45_000</output>

<result>45_000</result>