Answer:
It would have been longer.
Explanation:
Lets assume the Sun angle = θ
Distance between Syene and Alexandria = D
Circumference of Earth = C
As per Eratosthenes' calculations,
[tex]\frac{\theta}{360} =\frac{D}{C}[/tex]
From the above equation it is evident that if the circumference decreases value of θ will increase which implies that the shadow length would be longer as compared to that on the Earth.