Answer:
So, 
Step-by-step explanation:

To evaluete this expression we apply exponential property

IF any expression has exponent 0 then the value is 1 always
for example, 

because exponent is 0
So, 
Answer is 30
you can use PEMDAS to help you on further questions like this
P-Parenthesis
E-Exponents
M/D-Multiplication/Division solved in order from left to right
A/S-Addition/Subttaction solved in order from left to right
<span>I believe the answer is 60.75pi, calculated as follows:</span>
Area of Circle: (9 * 9) * pi = 81pi
Area of Shaded Area = (90 / 360) * 81p = 20.25pi
81pi - 20.25pi = 60.75pi