Step-by-step explanation:
The diameter of the circle is 4 inches so its radius r is 2 inches. The area of the circle is
[tex]A = \pi r^2 = \pi(2\:\text{in})^2 = 12.57\:\text{in}^2[/tex]
The circumference C of the circle is
[tex]C = 2\pi r = 2\pi(2\:\text{in}) = 12.57\:\text{in}[/tex]
