Area = pi*r^2
Circumference = 2pi*r
Step 1: find the radius from area
81pi=pi*r^2
81=r^2
9=r
Step 2: plug in radius to the circumference equation
Circumference = 2pi*r
18pi is the answer, otherwise know as 56.52 as well.
Answer:
Option C is correct.
Step-by-step explanation:
We need to multiply the following terms using vertical multiplication method
3x^2-5x+1
x x^2+2x+4
The vertical multiplication is shown in the figure attached.
The result is: 3x^4+x^3+3x^2-18x+4
So, Option C is correct.