Increase the radius twice and you will get in all the Earth's surface: the area will increase only twice instead of four times as it would on a plane.

把半径增加两倍，你就会得到整个地球的表面，面积只增加了两倍而不是如同在平面上的四倍。

youdao

We noted earlier there was more surface area on the front side, and this caused us no problems in use at all.

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