the question is asking you to find the circumfrance (the outside of the circle) so the formula you would use is:
C = 2πr
input the values you have into the formula
C= 2 x π x 3
(the radius is the distance between the very centre of the circle to the outside. it gives you the diameter which is the distance all the way across the circle so just half the diameter, which gives you a radius of 3)
put that into your calculator and youll get the answer
C= 18.8495559215
(i rounded the answer to two decimal places = 18.85ft)
Since he wants to buy a game system you can also write this as an inequality, if the amount of the game system has any relevance in the problem. 8.25*H >= 206.25