Hello there!
21 * 3.14 = 65.94
Thus,
The circumstances of the swimming pool is 65.94
SOLUTION
In this question, we are meant to expand the expression:

Answer: 
Step-by-step explanation:
You have this expression:

You already know that the value of the variable "x" is:

And the value of the variable "y" is:

Therefore, you can substitute the value of the variable "x" and the value of the variable "y" into the expression.
Then you get:

The answer for radius= 11 ........