Verified answer

The circle's radius is half the diameter or 4pi/2 = 2pi.

Since area is A = pi(r^2) when we set r= 2pi we get

A = pi(2pi)^2 = pi(4pi^2) = 4pi^3 so a = 4 and b = 3.

12

A = π(4π/2)²

= 4π³

= aπ^b

ab = 4*3 = 12

The area of a circle is A:

A = pi * r^2

since the the diameter is 4 pi, then the radius is 2 pi. Therefore A is:

A = pi * 4 pi^2 = 4 pi ^ 3 = a pi^b

Comparing leads to :

a = 4 and b = 3

area = πr²

r = d/2 = 4π/2 = 2π

r² = 4π²

plug 4π² into the formula for area.

area=(pi)r^2

r=4(pi)/2

(pi)*(4(pi)/2)^2 = 16(pi)^3/4 = 4(pi)^3

a=4

b=3

ab=12