Answer
$ \sqrt {52}$ or 7.21 unit
Work Step by Step
To calculate distance between given points (4,7) and (8,1), we will use distance formula-
r = $ \sqrt { (x_{2} - x_{1}) ^{2} + (y_{2} - y_{1}) ^{2}}$
= $ \sqrt { (8 - 4) ^{2} + (1 - 7) ^{2}}$
= $ \sqrt { (4) ^{2} + (-6) ^{2}}$
= $ \sqrt {16 +36}$
= $ \sqrt {52}$
= 7.21 unit
