Can someone help please

A(t)=728(1+0.04)^t how much money did aditya originally invest

Lena reflected this figure across the x-axis. she writes the vertices of the image as a'(−2, 8), b'(−5, 6), c'(−8, 8), d'(−4, 2).

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.