The Formula to find the Area of a circle using the radius is:

r = 8
So:



And you get about 201.06193
So, the area of a circle with a radius of 8 is about 201.06
Hope this Helps :)
3.4 understood by the concept. idk
Answer:
4 stations
Step-by-step explanation:
If we need to be at least 98% certain that an enemy plane flying over will be detected by at least one station, we must ensure that there is at most a 2% chance that no radar stations detect the plane.
The probability that a single radar station does not detect the plane is 0.35.
For n radar stations:

Rounding up to the next whole station, at least 4 stations are needed.