As the park is rectangular, all the angles are 90∘
In right angled ΔABC, AC2=AB2+BC2 [by Pythagoras theorem]
⇒AC2=(60)2+(80)2=3,600+6,400⇒AC2=10,000⇒AC=√10,000⇒AC=100 m
If she goes through AB and AC, then total distance covered = (60 + 80) m = 140 m
∴ Difference between two paths = (140 - 100) m = 40 m