The answer is in the picture below
Answer:
507
Step-by-step explanation:
As they said, I will be using 3 as pi.
(pi)
(radius squared)
Without annotations: 

; 


Answer: 21
Step-by-step explanation: In these types of problems, you use inverse operations. The inverse operation for multiplying is dividing. 42 divided by 2 is 21.
-4^2 is the same as -4*-4
-4*-4=16
-4^2= 16
-4^2 is the exponent.
I hope this helps!
~kaikers