Answer
(b). $3 \sqrt 5$
Work Step by Step
To calculate distance between given points (-2, 8) and (4, 5), we will use distance formula-
r = $ \sqrt { (x_{2} - x_{1}) ^{2} + (y_{2} - y_{1}) ^{2}}$
= $ \sqrt { (-2 - 4) ^{2} + (8 - 5) ^{2}}$
= $ \sqrt { (-6) ^{2} + (3) ^{2}}$
= $ \sqrt {36 +9}$
= $ \sqrt {45}$
= $ \sqrt {9\times5}$
= $ \sqrt {9} \sqrt 5$
= $3 \sqrt 5$
