Answer:
72º
Step-by-step explanation:
In order to calculate this you have to remember that the center angle of any polygon measures 360º, so what we do is just divide those 360 by the number of angles that you will find in the polygon, the number of angles equals the number of sides, so the pentagon has 5 sides, it will also have 5 angles. So we just divide the 360/5=72
So the smallest angle of rotational symmetry that maps a regular pentagon onto itself will be 72º