Question 326612
Let d(A,B) = distance from point A to point B.

d(A,B) = sqrt[(2 - 6)^2 + (-1 + 4)^2]

d(A,B) = sqrt[16 + 9]

d(A,B) = sqrt[25]

d(A,B) = 5

So, the length of segment AB is 5.

Understand?