If you don't need an exact answer, 9 is the answer, as she'd walk around it 54 times.
We know that
[area of circular cookie]=pi*r²
r=2.5 in
[area of circular cookie]=pi*2.5²----> 19.63 in²
the answer is
the area of circular cookie is 19.63 in²
There will be 17 quarters in the bag (12 which are state and 5 which are regular). The probability of the state quarters picked on the first try would be 12/17 while the probability of the second will be 5/17. If Rees put the state quarter back in the jar, then probability that the second quarter will be a regular quarter will remain 5/17.

Actually Welcome to the concept of Geometric Mean (leg) theorem.
So according to the rule, we know that, here altitude = h and left side is 6 and right side is 14 , so we get as,
==> altitude/left = right/altitude
==> h/6 = 14/h
==> h^2 = 14*6
==> h^2 = 84
2.) so now we apply the Pythagoras theorem in triangle ∆DCB
so we get as,
==> (14)^2 + h^2 = a^2
==> 196 + 84 = a^2
==> 280 = a^2
==> a = √280
==> after simplified => a = √70*4
==> a = 2√70 units
hence the correct answer is a => 2√70 units.