SOLUTION: how long is the line that joins the points A (2,1) and B (8,2)?

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Question 393644: how long is the line that joins the points A (2,1) and B (8,2)?
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
Lines have infinite length, including the line that passes through A and B.

But if the problem is to find the length of the line segment whose endpoints are A and B, then we can use the distance formula, d+=+sqrt%28%28x%5B2%5D-x%5B1%5D%29%5E2+%2B+%28y%5B2%5D-y%5B1%5D%29%5E2%29:
d+=+sqrt%28%288-2%29%5E2%2B%282-1%29%5E2%29
which simplifies as follows:
d+=+sqrt%28%286%29%5E2%2B%281%29%5E2%29
d+=+sqrt%2836%2B1%29
d+=+sqrt%2837%29
So the distance between A and B (or the length of line segment AB) is sqrt%2837%29.