1 kilometer = 2 miles. Then ten thousand miles is 5,000 kilometers, and a radius of ten thousand miles should be understood as a circle with a radius of five thousand kilometers.

There are two interpretations of a square circle:

(1) One is the area of ??a circle with a specified radius. The format of this usage will have a range description, such as "within a ten-mile radius." "This way of saying it refers to an area with a radius of ten miles.

(2) Another one refers to the "length around", or "the length around a circle", which is similar to the concept of perimeter. The format of this usage generally only talks about the distance and does not include a range description, such as "how many miles in a radius".

The radius of Liangshan Bo is eight hundred miles. It is suitable for the second usage, that is, the distance around Liangshan Bo in a certain way is eight hundred miles.

The first usage is suitable for the first usage, that is, with a certain point as the center, there is no human habitation within a range of ten miles away from the center.

Notes:

1. The mandatory evacuation area near nuclear radiation now reaches a radius of 20 kilometers, and the government has recommended that people living within 30 kilometers also evacuate.

2. They are a godsend for those who can't get lost within a three-mile radius of their home, and they are also great fun for those who like to find where things are.

3. If there is any dangerous object within ten miles, it will definitely find you.

4. In view of the unpredictability of this volcano, Indonesian officials expanded the "danger zone" to a radius of 20 kilometers.