This question is asking for the circumference of these circles, since it is asking for the edge of the pie. The formula for the circumference of a circle can be found by using 
or 
With that being said, let's get solving!
The first question only asks us to do 3.14 * 5, which is 15.7 inches.
The second question requires us to add a 2 into the equation. So our equation would be 3.14 * 7, which is 21.98 inches.
The third question gives us the diameter again, so our equation would be 3.14 * 9. The answer is 28.26 inches.
With that being said, let's get solving!
The first question only asks us to do 3.14 * 5, which is 15.7 inches.
The second question requires us to add a 2 into the equation. So our equation would be 3.14 * 7, which is 21.98 inches.
The third question gives us the diameter again, so our equation would be 3.14 * 9. The answer is 28.26 inches.