Slope of line joining the points (2, -3) and (-5, 1) is m1 \(=\frac{1-(-3)}{-5-2}=\frac{1+3}{-7}\) = -4/7
Slope of line joining the points (4, 5) and (0, -2) is m2 \(=\frac{-2-5}{0-4}=\frac{-7}{-4}\) = 7/4
Now, m1 m2 = \(\frac{-4}{7}\times\frac{7}{4}\) = -1
which is condition that both lines are perpendicular.