Answer:
The distance reduces to 0 as you go from 0° to 90°
Explanation:
The question requires you to find the distance using different values of L and check the trend of the values.
Given C=2×pi×r×cos L where L is the latitude in ° and r is the radius in miles then;
Taking r=3960 and L=0° ,
C=2×
×3960×cos 0°
C=2×
×3960×1
C=7380

Taking L=45° and r=3960 then;
C= 2×
×3960×cos 45°
C=5600.28

Taking L=60° and r=3960 then;
C=2×
×3960×cos 60°
C=3960

Taking L=90° and r=3960 then;
C=2×
×3960×cos 90°
C=2×
×3960×0
C=0
Conclusion
The values of the distance from around the Earth along a given latitude decreases with increase in the value of L when r is constant