Answer:
4:5
Step-by-step explanation:
Ratio compares two values. The ratio of nickels to pennies is:

A regular octagon has 8 sides, so it would coincide exactly each time the vertices fall into the same places. In one full 360-degree rotation, any "selected" vertex would fall into all 7 other vertices one after the other, before going back to its original position. Therefore, there would be 8 times during the rotation that the octagon coincides with the preimage.
25 and 1/4 thats the answer