This is the code I have written and it should tell me the radius of the circle after but instead I keep getting an error.

PI = 3.141593 radius_p = float(input('radius')) perimeter = 2 * PI * radius_p print('perimeter: ') + str(perimeter) # Ask the user for the radius of the room # Calculate the perimeter # Print the perimeter this is what I get after ``` TypeError Traceback (most recent call last) <ipython-input-80-ba1678e7ffca> in <module>() 2 radius_p = float(input('radius')) 3 perimeter = 2 * PI * radius_p ----> 4 print('perimeter: ') + str(perimeter) 5 # Ask the user for the radius of the room 6 # Calculate the perimeter TypeError: 'str' object is not callable

## Answer

The issue is that the `print()`

function prints a value to the shell or the console without returning anything. This is why when you are concatenating `print()`

which returns `NoneType`

with a `str()`

function which is in string format, it results in an error. Python doesn’t allow concat operation with variables of different types. This is what you should correct your code to.

PI = 3.141593 radius_p = float(input('radius')) perimeter = 2 * PI * radius_p print('perimeter:', str(perimeter))

You should get an output like the one I did below by entering 4.

**Note:** If the problem persists then you need to share the full code with us because **you might be using the str object as a variable name** somewhere which is incorrect.