A vegetable greenhouse is 10 meters long and its cross-section is a semicircle with a radius of 1 meter. Plastic film is used for the greenhouse (closed at both ends). How many square meters of plastic film is needed to make this greenhouse?
一个蔬菜大棚，它的长10米，横截面是半径为1米的半圆．大棚用塑料薄膜(两端封闭)，制作这个大棚至少需要塑料薄膜多少平方米？
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 2</gadget>
<output>6.28</output>

<gadget id="calculator">3.14 * 1 * 2 * 10</gadget>
<output>62.8</output>

<gadget id="calculator">6.28 + 62.8</gadget>
<output>69.08</output>

<gadget id="calculator">69.08 / 2</gadget>
<output>34.54</output>

<result>34.54</result>