Lets assume that they are driving at an average of 70mph, and getting gas takes 10 minutes, and stopping to eat takes 30.
t=d/s
t=600/70
t=8.57
Stopping to eat twice is 30 x 2 = 60 (another hour)
and Gas is 10 x 3 = 30 minutes (0.5 hours)
Total time is,
8.57+1+0.5 =10.07
So the trip will take approx 10.7 hours total.
(This is using my assumptions, from my experience!)
Since it is a square that means each side is equal.
The perimeter is 24, and since there is four sides we would divide it by four to find the length of each side.
24/4 = 6
Each side is 6.
By looking at the picture, one side of the square, is the length of the radius.
The radius of the square is 6.
The only thing left to do is to find the circumference.
The circumference formulas are:
C =

d
C = 2

r
We can use the first one Diameter x pi (3.14)
To find the diameter we would just multiply the radius by two.
6 x 2 = 12
Diameter = 12
So multiply it by pi
12 x 3.14 = 37.68
or D 12
Whiteboard full of trigonometric facts that you need to know...
The awnser is 60 because
It is a cube so it has the smae amout of sides