Since you didn't list choices, I can only give you some guidance on the problem.
A kilometer is the length of 1000 meters. And a meter is about as tall as a normal desk height. So a kilometer is a relatively long distance compared to a desk.
It is also about half the length of a mile, or about 2 times around a normal athletic track.
Look for items that are long distance like that.
The answer must be A. For an explanation, please have a look at the picture.
2,3,8
2,8,3
3,8,2
3,2,8
8,2,3
8,3,2
6 triangles.
21 hundred million,64 thousand, and 50
