Answer:
Step-by-step explanation:
The base of a cone is simply a circle.
The formula for the area of a circle is A = πr^2.
Example: What is the area of the base of a cone, if the radius of the base is 5 cm?
Answer: A = π(5 cm)^2 = 25π cm^2
-(3/4) (12)+1 = -9+1=. -8
Your answer should be 81 for a. I got this result by multiplying 9 by 9.