Answer: 20 ft
Explanation:
The mirror is set away from the flagpole on the same scale set away from her.
The distance she stand's away from the mirror is 1/4 of the length of the distance between the mirror and the flag pole because she's 1/4 of the flagpole's size.
This means her size x4 is the size for the flag pole. This checks out because 12x4=48
So to find the height we must do 5x4
5x4=20